Methods for making appetizing and dentally efficacious animal chews

ABSTRACT

Described herein are chewable articles intended to be provided to animals for purposes including dental cleaning, breath freshening, nutrition, administration to the animal of beneficial agents, satisfaction of the animal&#39;s urge to chew, and general enjoyment by the animal. Also disclosed are apparatus and methods for making such chewable articles, the methods including the use of a processing aid to lubricate the article-forming apparatus, such as extruders, portioners, and molds, and to reduce the power requirements of such apparatus in the forming process.

CROSS-REFERENCES TO RELATED APPLICATIONS

This application is a continuation-in-part of U.S. non-provisionalpatent application Ser. No. 13/833,424, which was filed on 15 Mar. 2013(application Ser. No. 13/833,424 is entitled to priority to U.S.provisional patent application 61/625,598, which was filed on 17 Apr.2012) and is also entitled claim priority to U.S. provisional patentapplication 61/953,357, which was filed on 14 Mar. 2014.

BACKGROUND OF THE DISCLOSURE

The disclosure relates generally to the field of chewable products foranimals, such as pet treats, that promote engagement and oral health.

Certain animals, especially dogs, but also including horses, ruminants,and rodents, are known to chew various articles for purposes other thanfood consumption. It is believed that such chewing behavior satisfies ananimal's urge to chew and that such chewing can have beneficial effectsfor the dental health and hygiene of the animal.

A wide variety of products are commercially available that can be chewedby animals, especially for domesticated dogs kept as pets. Many of theseproducts are designed to be appetizing to dogs, such as by inclusion offlavorants or aromants that simulate the flavors or aromas of foodsenjoyed by dogs. Many of these products are also designed to beconsumable, as well as to provide at least some limited dental benefits,such as frictional wiping of tooth surfaces. However, existing animalchew products have several shortcomings.

Such products provide relatively limited dental health benefits, in thatabrasion and wiping effects exerted by such chews on animal teeth tendto be substantially limited to primary biting surfaces (e.g., tips ofincisors and canine teeth and grinding surfaces of molars andpremolars). Some available chews soften substantially upon chewing orfracture into large or sharp fragments, presenting risks of injuries tothe throat and other parts of the digestive system. Portions of someanimal chew products (e.g., especially dough-based or biscuit-likeproducts) dissolve or become pasty when they absorb liquid, such assaliva, and can leave stains and other residue on surfaces when a wetproduct contacts the surface. Target animals tend to lack interest insome available animal chew products, whether because of insufficientlyenticing taste or smell, objectionable texture or consistency,cumbersome or non-appealing size and shape, disproportionate portionsize, or other reasons.

A need exists for improved animal chews which can confer benefits toanimals having an urge to chew. The subject matter disclosed hereinrelates to animal chews which improve upon or overcome one or more ofthe shortcomings of previously-known products.

BRIEF SUMMARY OF THE DISCLOSURE

This disclosure relates to animal chews that have a consumable portion.The consumable portion includes a chewable matrix and has dimensionsselected to fit within the oral cavity of an animal such as a dog. Thecomposition of the chewable matrix includes i) about 9-17 wt % protein,ii) about 40-50 wt % starch, iii) water, and iv) about 0.5-10 wt % ofone or more or more saccharidic processing aids. The compositionoptionally includes a humectant, such as one or both of glycerol andpropylene glycol. The water and (if present) the humectant(s) conferchewable plasticity to the chewable matrix in combination with its othercomponents. The chewable matrix should also include an orally activeingredient, such as one or more of dental prophylactic ingredients,breath agents, and pharmaceutical agents. The matrix preferably includesat least one orally active ingredient in an amount that is temporallyefficacious (i.e., exerts its desired effect during the time the chewcan be expected to remain in the animal's mouth during chewing).

The precise identity, form, and nature of the starch in the chew is notcritical. However, some starches and starch combinations can be morebeneficial than others for the uses set forth herein. For example, it ispreferable that the chewable matrix includes 10-20 wt % amylose.Similarly, it can be desirable if at least about 50 wt % of the starchin the chewable matrix is gelatinized and even more desirable if atleast about 80 wt % of the starch is gelatinized. Edible starch obtainedfrom a variety of sources can be used. One suitable source is rice, anda chewable matrix that includes 30-40 wt % starch obtained from rice(e.g., in the form of ground brewer's rice) has beneficial properties.Other suitable sources of starches include wheat, corn, other cereals,sago palm, potatoes, sweet potatoes, tapioca, and yucca. Some starches(e.g., dextrins) can function both as a starch and as a saccharidicprocessing aid.

Also useful are modified starches, such as those generally described asmodified food starches. For example, the chewable matrix can include 4-8wt % of an acid-thinned starch, a dextrin, or a combinations of these.

The saccharidic processing aid can be a mono-, di-, or oligosaccharideand can reduce the amount of water which must be included in theformulation in order to retain the processability and chewability of thematrix made from the formulation. Suitable saccharidic processing aidsinclude dextrins, maltodextrins, and simple sugars and sugar alcoholssuch as glucose, sucrose, fructose, xylose, xylitol, and sorbitol.Oligosaccharidic processing aids derived from starches can contributeboth to the starch content of the formulation and to its processabilityand chewability characteristics.

As with starches, the precise identity, form, and properties of anyhumectant included in the chewable matrix is not critical. For example,the humectant can be one or more of glycerol, propylene glycol, or otherknown humectants, and can be present in the chewable matrix in an amountthat is about 4-12 wt % of its total composition. In one suitableembodiment, the chewable matrix includes 2-10 wt % of at least onehumectant and 14-18 wt % water.

Of course, the chewable matrix can include ingredients other thanproteins, starches, water, humectants, and orally active ingredients.Any of a wide variety of agents known to be desirable in animal chews,foods, or medicaments can be included. Examples of suitable additionalingredients include vitamins, minerals, flavorants, aromants, colorants,and preservatives.

A variety of orally active ingredients can be included in the chewablematrix. They can be contained within one or move cavities within thematrix, coated on the outside of the matrix, dispersed in discrete(ordered or random) portions of the matrix, or dispersed substantiallyhomogenously throughout the chewable matrix. Examples of suitable orallyactive ingredients include dental prophylactic ingredients, breathagents, pharmaceutical agents, and combinations of these.

Dental prophylactic ingredients include various abrasives, such asparticulate and fibrous abrasives. Such abrasives preferably exhibit ahardness lower than the hardness of teeth of the animal to which thechew will be given (i.e., so as to avoid harming the enamel or othertooth surfaces), but is preferably harder than substances thatundesirably adhere to teeth. Such undesirably adherent materials includeplaque, tartar, odorous substances, and biological agents (e.g.,bacteria and biofilms) that can induce diseases (e.g., gingivitis) orundesirable conditions (e.g., halitosis). The chewable matrix caninclude 2-10 wt % of at least one abrasive, for example. Suitableparticulate abrasives include a mineral powders (e.g., one or more ofgypsum, titanium dioxide, silica, and calcium carbonate),naturally-occurring polymers such as powdered cellulose, and syntheticpolymers. Plant particles (e.g., ground husks, brans, or hulls) can beused as particulate abrasives as well. Suitable fibrous abrasivesinclude natural fibers such as plant fibers that are indigestible by theanimal (e.g., cellulose) and synthetic fibers such as nylons.

Important classes of dental prophylactic ingredient include anti-plaqueagents, anti-tartar agents, and tooth-strengthening agents (e.g.,fluoride salts). Examples of suitable anti-tartar agents include metalchelating agents (e.g., polyphosphates such as one or more of sodiumtripolyphosphate (STPP), tetrasodium pyrophosphate, and sodiumhexametaphosphate).

Another important class of orally active ingredients is breath agents,such as one or more of plants, plant extracts, and bicarbonate salts.

Yet another important class of orally active ingredients ispharmaceutical agents. The animal chews described herein are suitablefor delivering pharmaceutical agents intended for administration to agastrointestinal (GI) tract locus proximal to the stomach, such as anoral tissue (e.g., gingival pockets) or the esophagus. Pharmaceuticalagents that can be delivered using the chews include antibiotics,anti-inflammatory agents, and topical analgesics, for example. The chewscan also be used to administer to an animal pharmaceutical agentsintended for systemic administration by way of absorption through mucosaof the upper GI tract. Chews which include bad-tasting ingredients(e.g., many pharmaceutical agents) can include a taste-maskingingredient in an amount sufficient to render the chewable matrixpalatable to the animal.

An important characteristic of the animal chews described herein is thatthey can be readily manufactured in a wide variety of sizes, shapes,colors, and configurations. Such characteristics can be selected toappeal to one or both of an animal and a human that owns or cares for ananimal. By way of example, chews intended for dogs can have size, shape,and texture characteristics that dogs find appealing while having visualcharacteristics that appeal to dog owners. A chew having a ‘bone-shaped’conformation including an elongate shaft interposed between twoflattened bi-lobed ends, for example, can appeal both to humans (whoassociate ‘bone’ chewing with dogs) and to dogs (which may be lessinterested in the ‘bone’ shape of the chew than in the sensationsassociated with chewing it). Color, shape, and surface indicia (orornamentation) can also be used as indicators of the flavor, texturequalities, or components of the chews. For example, two chews differingin added flavorants or aromants can be made to have different colors(e.g., so that human purchasers can differentiate the chews withouttasting or smelling them). Further by way of example, chews whichinclude a pharmaceutical agent can have the identity of the agent,dosing instructions, or other relevant information printed upon orimprinted into the chew. Such indicia can also identify functionalproperties (e.g., breath freshening or tartar scouring) of the chews.

Apart from cosmetic and informational functionality, the shape of thechews described herein can enhance the dental efficacy of the chews andtheir attractiveness as chewing substrates for animals. For example,nubs, ridges, and other surface features can serve to scour tooth andgum surfaces as an animal gnaws or bites the chew. The shape andtopography of the chews can also encourage chewing thereupon by animalssuch as dogs. By way of example, a ‘bone’ shaped chew having flattenedends that are rotationally offset from one another (e.g., by 30, 45, 60,or 90 degrees) about the axis of the shaft of the ‘bone’ can be heldbetween the front paws of a dog while it gnaws on the opposite end ofthe chew. Surface features present on the shaft or on the gnawed end canscour the dog's teeth, lips, and gums as it does so. For example, theconsumable portion of an animal chew can have a plurality of nubsextending outwardly from it. The nubs can have dimensions compatiblewith being interposed between teeth of the animal when the animal graspsthe chew in its mouth.

In a conformation preferred for use with dogs, the chew has a‘bone-shaped’ conformation including an elongate shaft interposedbetween two flattened bi-lobed ends that are rotationally offset fromone another about the axis of the shaft. The chew has two opposed,twisted, generally parallel flat faces each extending across the endsand shaft, and each of the faces bears nubs thereon. The chew can haveridges on the transitional faces interposed between the two flat faces.

The textural qualities of the animal chew described herein are alsoimportant. The texture of the chew can contribute to its functionality,to its appeal as a chewing substrate for animals, and to itsdesirability to humans for use as a food, health-enhancing product, ortoy for animals. In one embodiment, the chewable matrix of the chewexhibits sufficient friability that substantially all of the consumableportion of the chew can be consumed by the animal in not more than fourhours of composite chewing time. In another embodiment, the chewablematrix of the chew exhibits sufficient integrity that a substantialportion of the consumable portion of the chew remains non-consumed bythe animal after at least one minute of composite chewing time. In yetanother embodiment, the chewable matrix of the chew exhibits sufficientrigidity that the chewable matrix does not fracture until it has beenchewed at least about 25 times by the animal. In still anotherembodiment, the chewable matrix of the chew exhibits sufficientductility that the animal is able to leave a visible indentation in thesurface of the chewable matrix upon biting the chew one time. The chewdescribed herein can have a resilient portion fixedly attached to aconsumable portion of the chew at an attachment site. In thisembodiment, the resilient portion is substantially not consumable by theanimal and can prevent the animal from swallowing the remnant thatremains after the bulk of the chew has been consumed by the animal.

The favorable characteristics of the chews described herein cancomplement one another. By way of example, the texture and shape of thechewable matrix and the content of the orally active ingredient in thechew can be selected so that daily consumption of a chew by an animallimits plaque accumulation on the teeth of an animal to a degree that isapproximately equivalent to limits on plaque accumulation that areachievable through brushing the animal's teeth using a veterinarydentifrice every other day. Similarly, the chews can be designed to haveanti-tartar, disease (e.g., gingivitis) preventive, or breath fresheningfunctionality equivalent to that achievable through other means.

In addition to being objects that animals find desirable to bite and/orgnaw, the animal chews described herein can exhibit dental efficacy,such as tooth-cleaning functionality. The chews can be used to clean theteeth of an animal by providing the chew to the animal. Chews used forthis purpose should, of course be designed to include one or more orallyactive tooth cleaning ingredients (e.g., dentifrices, abrasives, oranti-tartar agents) to effect cleaning of the animal's teeth during theexpected residence time (or expected number of chews prior toconsumption) that can be expected for the animal to which the chew isgiven. Chews that contain veterinary pharmaceutical agents can be usedto deliver those agents to animals that gnaw upon or consume the chews.

Disclosed herein are a variety of methods of making the animal chewdescribed herein, including its chewable matrix for an animal chew.Generally speaking, these methods include the steps of

1) combining to form a substantially homogenous mixture: i) about 5-20wt % protein, ii) about 30-60 wt % starch, iii) about 20-30 wt % water,optionally including a humectant in this amount, iv) about 0.5-10 wt %of a saccharidic processing aid, and v) an orally active ingredient;

2) heating the mixture above the gelatinization temperature of thestarch to form a melt;

shaping a portion of the melt into a matrix having dimensions selectedto fit within the oral cavity of the animal; and

cooling the matrix below the gelatinization temperature to yield thechewable matrix.

In these methods, the proportions water, humectant(s), and saccharidicprocessing aid(s) should be selected in amounts sufficient to conferchewable plasticity to the cooled chewable matrix, taking into accountany drying of the cooled matrix that will be performed (or performingsuch drying to achieve a desired final moisture content). The amount ofthe orally active ingredient should selected such that the chewablematrix comprises a temporally efficacious amount of the ingredient.

A variety of manufacturing methods can be used to practice thesemethods. For example, the melt can be portioned into billets prior toshaping the billets, for example, by compression molding.

In one embodiment of a compression molding process of this type, themelt is portioned into billets in a portioner and the billets arethereafter shaped in a rotary molder.

In this method, the portioner includes a plurality of portioner plates,each which bears a void extending through the portioner plate. Eachportioner plate is circumferentially attached to a rotatable hub at aposition at which rotation of the hub causes the portioner plate to passbetween a top plate that closely opposes one face of the portioner plateand a bottom plate that closely opposes the opposite face of theportioner plate. A billet volume is thereby defined by the void, aslimited by the opposition between the top and portioner plates, and bythe opposition between the bottom and portioner plates. The hub of theportioner is spaced apart from a nozzle that communicates with the voidin each portioner plate as the plate rotates about the hub. As the voidpasses the nozzle at a filling position, melt is expelled through thenozzle and passes into the void. The filled portioner plate is rotatedfrom the filling position, past the top and bottom plates, into adischarge position. There, the void contains a billet of melt that isequal to the billet volume. At the discharge position, a knock-outdevice displaces the billet from the void, transferring the billet tothe rotary mold.

In this method, the rotary mold includes multiple opposed pairs of uppermold plates and lower mold plates. These opposed pairs of plates arecircumferentially attached to a rotatable hub. The opposed upper andlower mold plates are movable with respect to one another in thedirection parallel to the axis of the hub (i.e., one or both of theseplates can be moved toward and away from the other). Each upper moldplate bears an upper molding cavity on the face opposite the lower moldplate, and each lower mold plate bears a lower molding cavity on theface opposite the upper mold plate. Each of the upper and lower moldplates is also inclinable between a lowered position substantiallyperpendicular to the axis of the hub and a raised position substantiallyparallel to the axis of the hub. Each pair of upper and lower moldplates being sequentially rotatable between at least five positions:

i) a filling position in which the upper and lower mold plates arespaced apart from one another and at least one of the upper and lowermolding cavities is positioned to receive the billet as it is displacedfrom the void in the portioner plate,

ii) one or more compression positions in which both the upper and lowermold plates are in their respective lowered positions and at least oneof the upper and lower mold plates is moved toward the other;

iii) a closed position in which the upper and lower mold plates areclosely opposed against one another and the cavity defined by the upperand lower molding plates defines the form into which each billet isshaped;

iv) one or more casting positions in which the upper and lower moldplates remain closely opposed against one another as the hub rotates;and

v) a discharge position in which at least one of the upper and lowermold plates is in its raised position.

In this method, the portioner portions the melt into billets which aredisplaced from the portioner, received in a mold plate of the rotarymolder, and thereafter shaped in and discharged from the rotary molder.

In alternative manufacturing methods the melt can be substantiallysimultaneously portioned and shaped, such as by using a rotary mold orby injection molding.

In the manufacturing methods described herein, the temperature of themelt is preferably maintained below the boiling point of the melt priorto shaping it. One or more of the additional ingredients describedherein can be added to the melt prior to shaping it, either prior tomelt formation or thereafter.

Also disclosed herein is an apparatus for forming molded foodstuffs froma moldable extrudate. The apparatus includes a portioner and a rotarymolder.

In this apparatus, the portioner includes multiple portioner plates,each bearing a void extending therethrough. Each portioner plate iscircumferentially attached to a rotatable hub at a position at whichrotation of the hub causes the portioner plate to pass between a topplate that closely opposes one face of the portioner plate and a bottomplate that closely opposes the opposite face of the portioner plate. Abillet volume is thereby defined by the void, by the opposition betweenthe top and portioner plates, and by the opposition between the bottomand portioner plates. The hub is spaced away from a nozzle thatcommunicates with the void in each portioner plate as the plate rotatesabout the hub past the nozzle. At a position designated the fillingposition, extrudate expelled through the nozzle can pass into the void.Portioner plates are rotatable from the filling position, past the topand bottom plates, into a discharge position. There, the void contains abillet of extrudate that is roughly equal in volume to the billetvolume. The apparatus includes a knock-out device for displacing thebillet from the void at the discharge position.

In this apparatus, the rotary mold includes multiple opposed pairs ofupper mold plates and lower mold plates circumferentially attached to arotatable hub. Each pair of upper and lower mold plates is movable withrespect to one another in the direction parallel to the axis of the hub(i.e., opposed faces of the plates can be moved toward and away from oneanother, although only one plate need be able to so move to effect suchrelative movement). Each upper mold plate bears an upper molding cavityon the face opposite the lower mold plate, and each lower mold platebearing a lower molding cavity on the face opposite the upper moldplate. Each of the upper and lower mold plates is inclinable between alowered position substantially perpendicular to the axis of the hub anda raised position substantially parallel to the axis of the hub (i.e.,the pair can be opened outwardly away from the shaft, like a clam shellattached to the hub at its hinge). Each pair of upper and lower moldplates is sequentially rotatable between at least five positions:

i) a filling position in which the upper and lower mold plates arespaced apart from one another and at least one of the upper and lowermolding cavities is positioned to receive the billet as it is displacedfrom the void in the portioner plate,

ii) a series of compression positions in which both the upper and lowermold plates are in their respective lowered positions and at least oneof the upper and lower mold plates is moved toward the other;

iii) a closed position in which the upper and lower mold plates areclosely opposed against one another and the cavity defined by the upperand lower molding plates defines the form of the foodstuff into whicheach billet is shaped;

iv) a series of casting positions in which the upper and lower moldplates remain closely opposed against one another as the hub rotates;and

v) a discharge position in which at least one of the upper and lowermold plates is in its raised position.

The portioner portions the extrudate into billets which are displacedfrom the portioner, received in a mold plate of the rotary molder, andthereafter shaped in and discharged from the rotary molder.

Disclosed herein is a method of enhancing the emotional bond between ahuman and an animal. This method involves the human repeatedly visiblyproviding the animal chew described herein to the animal in response tothe need by the animal for the article. The bond between the human andthe animal is thereby enhanced.

BRIEF SUMMARY OF THE SEVERAL VIEWS OF THE DRAWINGS

The patent or application file contains at least one drawing executed incolor. Copies of this patent or patent application publication withcolor drawing(s) will be provided by the Office upon request and paymentof the necessary fee.

FIG. 1, consisting of FIGS. 1A, 1B, 1C, 1D, 1E, 1F, and 1G, is acollection of views of an embodiment of an animal chew described herein.FIG. 1A is a perspective view, in which the front, side, and bottom ofthe chew can be seen. Other views shown are front elevation (FIG. 1B),rear elevation (FIG. 1C), top plan (FIG. 1D), bottom plan (FIG. 1E),side elevation (FIG. 1F), and opposite side elevation (FIG. 1G) views.

FIG. 2, consisting of FIGS. 2A, 2B, 2C, 2D, 2E, 2F, and 2G, is acollection of views of an embodiment of an animal chew described herein.FIG. 2A is a perspective view, in which the front, side, and bottom ofthe chew can be seen. Other views shown are front elevation (FIG. 2B),rear elevation (FIG. 2C), top plan (FIG. 2D), bottom plan (FIG. 2E),side elevation (FIG. 2F), and opposite side elevation (FIG. 2G) views.

FIG. 3, consisting of FIGS. 3A, 3B, 3C, 3D, 3E, 3F, and 3G, is acollection of views of an embodiment of an animal chew described herein.FIG. 3A is a perspective view, in which the front, side, and bottom ofthe chew can be seen. Other views shown are front elevation (FIG. 3B),rear elevation (FIG. 3C), top plan (FIG. 3D), bottom plan (FIG. 3E),side elevation (FIG. 3F), and opposite side elevation (FIG. 3G) views.

FIG. 4, consisting of FIGS. 4A, 4B, 4C, 4D, 4E, 4F, and 4G, is acollection of views of an embodiment of an animal chew described herein.FIG. 4A is a perspective view, in which the front, side, and bottom ofthe chew can be seen. Other views shown are front elevation (FIG. 4B),rear elevation (FIG. 4C), top plan (FIG. 4D), bottom plan (FIG. 4E),side elevation (FIG. 4F), and opposite side elevation (FIG. 4G) views.

FIG. 5, consisting of FIGS. 5A, 5B, 5C, 5D, 5E, 5F, and 5G, is acollection of views of an embodiment of an animal chew described herein.FIG. 5A is a perspective view, in which the front, side, and bottom ofthe chew can be seen. Other views shown are front elevation (FIG. 5B),rear elevation (FIG. 5C), top plan (FIG. 5D), bottom plan (FIG. 5E),side elevation (FIG. 5F), and opposite side elevation (FIG. 5G) views.

FIG. 6, consisting of FIGS. 6A, 6B, 6C, 6D, 6E, 6F, and 6G, is acollection of views of an embodiment of an animal chew described herein.FIG. 6A is a perspective view, in which the front, side, and bottom ofthe chew can be seen. Other views shown are front elevation (FIG. 6B),rear elevation (FIG. 6C), top plan (FIG. 6D), bottom plan (FIG. 6E),side elevation (FIG. 6F), and opposite side elevation (FIG. 6G) views.

FIG. 7, consisting of FIGS. 7A, 7B, 7C, 7D, 7E, 7F, and 7G, is acollection of views of an embodiment of an animal chew described herein.FIG. 7A is a perspective view, in which the front, side, and bottom ofthe chew can be seen. Other views shown are front elevation (FIG. 7B),rear elevation (FIG. 7C), top plan (FIG. 7D), bottom plan (FIG. 7E),side elevation (FIG. 7F), and opposite side elevation (FIG. 7G) views.

FIG. 8, consisting of FIGS. 8A, 8B, 8C, 8D, 8E, 8F, and 8G, is acollection of views of an embodiment of an animal chew described herein.FIG. 8A is a perspective view, in which the front, side, and bottom ofthe chew can be seen. Other views shown are front elevation (FIG. 8B),rear elevation (FIG. 8C), top plan (FIG. 8D), bottom plan (FIG. 8E),side elevation (FIG. 8F), and opposite side elevation (FIG. 8G) views.

FIG. 9, consisting of FIGS. 9A, 9B, 9C, 9D, 9E, 9F, and 9G, is acollection of views of an embodiment of an animal chew described herein.FIG. 9A is a perspective view, in which the front, side, and bottom ofthe chew can be seen. Other views shown are front elevation (FIG. 9B),rear elevation (FIG. 9C), top plan (FIG. 9D), bottom plan (FIG. 9E),side elevation (FIG. 9F), and opposite side elevation (FIG. 9G) views.

FIG. 10, consisting of FIGS. 10A, 10B, 10C, 10D, 10E, 10F, and 10G, is acollection of views of an embodiment of an animal chew described herein.FIG. 10A is a perspective view, in which the front, side, and bottom ofthe chew can be seen. Other views shown are front elevation (FIG. 10B),rear elevation (FIG. 10C), top plan (FIG. 10D), bottom plan (FIG. 10E),side elevation (FIG. 10F), and opposite side elevation (FIG. 10G) views.

FIG. 11, consisting of FIGS. 11A, 11B, 11C, 11D, 11E, 11F, and 11G, is acollection of views of an embodiment of an animal chew described herein.FIG. 11A is a perspective view, in which the front, side, and bottom ofthe chew can be seen. Other views shown are front elevation (FIG. 11B),rear elevation (FIG. 11C), top plan (FIG. 11D), bottom plan (FIG. 11E),side elevation (FIG. 11F), and opposite side elevation (FIG. 11G) views.

FIG. 12, consisting of FIGS. 12A, 12B, 12C, 12D, 12E, 12F, and 12G, is acollection of views of an embodiment of an animal chew described herein.FIG. 12A is a perspective view, in which the front, side, and bottom ofthe chew can be seen. Other views shown are front elevation (FIG. 12B),rear elevation (FIG. 12C), top plan (FIG. 12D), bottom plan (FIG. 12E),side elevation (FIG. 12F), and opposite side elevation (FIG. 12G) views.

FIG. 13, consisting of FIGS. 13A, 13B, 13C, 13D, 13E, 13F, and 13G, is acollection of views of an embodiment of an animal chew described herein.FIG. 13A is a perspective view, in which the front, side, and bottom ofthe chew can be seen. Other views shown are front elevation (FIG. 13B),rear elevation (FIG. 13C), top plan (FIG. 13D), bottom plan (FIG. 13E),side elevation (FIG. 13F), and opposite side elevation (FIG. 13G) views.

FIG. 14, consisting of FIGS. 14A, 14B, 14C, 14D, 14E, 14F, and 14G, is acollection of views of an embodiment of an animal chew described herein.FIG. 14A is a perspective view, in which the front, side, and bottom ofthe chew can be seen. Other views shown are front elevation (FIG. 14B),rear elevation (FIG. 14C), top plan (FIG. 14D), bottom plan (FIG. 14E),side elevation (FIG. 14F), and opposite side elevation (FIG. 14G) views.

FIG. 15, consisting of FIGS. 15A, 15B, 15C, 15D, 15E, 15F, and 15G, is acollection of views of an embodiment of an animal chew described herein.FIG. 15A is a perspective view, in which the front, side, and bottom ofthe chew can be seen. Other views shown are front elevation (FIG. 15B),rear elevation (FIG. 15C), top plan (FIG. 15D), bottom plan (FIG. 15E),side elevation (FIG. 15F), and opposite side elevation (FIG. 15G) views.

FIG. 16, consisting of FIGS. 16A, 16B. 16C, 16D, 16E, 16F, and 16G, is acollection of views of an embodiment of an animal chew described herein.FIG. 16A is a perspective view, in which the front, side, and bottom ofthe chew can be seen. Other views shown are front elevation (FIG. 16B),rear elevation (FIG. 16C), top plan (FIG. 16D), bottom plan (FIG. 16E),side elevation (FIG. 16F), and opposite side elevation (FIG. 16G) views.

FIG. 17 is an end view of an animal chew as described herein, the chewhaving a colloquial dog-bone shape in which planes taken through each ofthe bicondylic ends and intersecting one another along the axis of theshaft are offset from one another by the angle identified in this figureas “ALPHA.”

FIG. 18 is an illustration of a colloquial dog-bone shape, whichconsists of a shaft having a pair of bicondylic ends.

FIG. 19 consists of FIGS. 19A, 19B. 19C, and 19D, and is a quartet ofdiagrams that show the effect of composition on setting time (FIGS. 19Aand 19C), hardness (FIG. 19B), and moisture retention (FIG. 19D) foranimal chew formulations made as described herein. In FIG. 19, “A,” “B,”and “C” represent content values (wt %) for “Starch A”, “Starch B,” andcellulose powder as described herein. Because each of the compositionstested included additional ingredients (e.g., about 38% brewers' rice)in amounts that totaled about 47 wt % of the composition, the diagramsshow only the varied components, which constitute the remaining ca. 53wt % of the composition.

FIG. 20 consists of FIGS. 20A, 20B, 20C, and 20D. FIG. 20A is a diagramof a billet-forming and -molding process for producing animal chews fromextruded materials as described herein. FIG. 20B is an image of a molduseful for molding such chews. In the image, a molded chew is shownemerging from a molding plate used to shape one side of the chew. Themold used to mold the exposed side of the chew has been removed and isvisible behind the mold from which the chew is emerging. FIGS. 20C and20D are top and side views of an apparatus described herein for use in acompression molding process for producing animal chews.

FIG. 21 consists of FIGS. 21A, 21B, and 21C. FIG. 21A is a diagram of aroll-molding process for producing animal chews from extruded materialsas described herein. FIGS. 21B and 21C are images of a manifold used tofacilitate delivery of extruded materials from the outlet of an extruderto the opposed molding cavities carried by a pair of rollers. In theside view of the manifold shown in FIG. 21B, the curved portions thatare opposed against the faces of the rollers are visible. The image inFIG. 21C is a view taken from the right side of the manifold shown inFIG. 21B, and the bore extending through the manifold (corresponding tothe notch in the curved surfaces visible in FIG. 21B) is visible.Extruded materials are carried through this bore and emerge into theopposed molding cavities at the surfaces of the rollers opposed againstthe curved surface.

FIG. 22 consists of FIGS. 22A, 22B, 22C, 22Ci, 22Cii, and 22Ciii. FIG.22A is a diagram of a conveyor molding process for producing animalchews from extruded materials as described herein. FIGS. 22B and 22C arefront and side view, respectively of an embodiment of the formingconveyor 500 depicted in the process shown in FIG. 22A, the formingconveyor 500 comprising at least one convex shaping member 510 and atleast one concave shaping member 520 having a complementary shape, sothat material introduced between the two members (as indicated by “BoneFeed” in FIGS. 22B and 22C) can be shaped and have its surface molded asthe two members are urged against each other. FIGS. 22Ci and 22Cii areviews of the convex shaping member 510, FIG. 22Cii showing the shapingsurface of the member and FIG. 22Ci showing a face of the member thatcan be attached to a conveyor mechanism. FIG. 22Ciii is a view of theconcave shaping member 520 showing its shaping surface.

FIG. 23 consists of FIGS. 23A, 23B, 23C, 23D, 23E, 23F, 23G, 23H, and23J (No figure is designated 23I). Each of these figures is an image ofan embodiment of the animal chews described herein, with the chew shownin FIG. 23E being broken along its shaft to illustrate that the interiorof the chew has a composition visually different from its exterior.

FIG. 24 consists of FIGS. 24A, 24B, 24C, and 24D. Each of these figuresis an image that depicts surface features of embodiments of chewsdescribed herein. Each of the embodiments has a “twisted dog-bone”shape, which consists of a shaft having a pair of bicondylic ends, thebicondylic ends of each chew being angularly offset from one another. Inthe embodiments shown in FIGS. 24A and 24B, text (here, the MILK-BONEregistered trademark of Del Monte Corporation, San Francisco Calif.) ismolded into the surface of the chew. The embodiment shown in FIG. 24Ahas rounded conical nubs extending from the front and rear surfacesthereof. The embodiment shown in FIG. 24B has rounded conical nubsextending from the front surface thereof and ridges extending from therear surface thereof. The embodiment shown in FIG. 24C has both roundedconical nubs and ridges extending from the front and rear surfacesthereof. The embodiment shown in FIG. 24D has ridges extending from thefront and rear surfaces thereof.

FIG. 25 consists of FIGS. 25A, 25B, 25C, 25D, and 25E. Each of thesefigures is an image that depicts surface features of embodiments ofchews described herein. FIG. 25A depicts rounded conical projectionsfrom a surface of a chew, the projections having approximately the samesize and height (the distance from the surface to the apex of theprojection). FIG. 25B depicts rounded conical projections from a surfaceof a chew, the projections having varying sizes and heights (two sizesand heights in this image). FIG. 25C depicts a chew surface havingprotruding therefrom ridges that have a wavy shape and that areapproximately parallel to one another. FIG. 25D depicts a surface havingboth rounded conical projections and ‘C’-shaped ridges projectingtherefrom. FIG. 25E depicts a surface having both rounded conicalprojections and wave-shaped ridges projecting therefrom.

FIG. 26 consists of FIGS. 26A, 26B, 26C, 26D, 26E, 26F, 26G, and 26H anddepicts a variety of shapes in which the animal chews described hereincan be formed.

FIG. 27 consists of FIGS. 27A, 27B, 27C, 27D, 27E, 27F, 27G, and 27H anddepicts a variety of shapes in which the animal chews described hereincan be formed.

FIG. 28 consists of FIGS. 28A, 28B, 28C, 28D, 28E, and 28F and depicts avariety of shapes in which the animal chews described herein can beformed.

FIG. 29 consists of FIGS. 29A, 29B, and 29C and depicts a variety ofshapes in which the animal chews described herein can be formed.

FIG. 30 consists of FIGS. 30A, 30B, 30C. 30D, 30E, 30F, 30G, and 30H anddepicts a variety of shapes in which the animal chews described hereincan be formed.

FIG. 31 is a view of an embodiment of an animal chew described herein.

FIG. 32 is a view of an embodiment of an animal chew described herein.

FIG. 33 is a view of an embodiment of an animal chew described herein.

DETAILED DESCRIPTION

Individuals often seek to provide for both the well-being and thehappiness of animals within their care. Animals that tend to chew theirfood can obtain both of these benefits from chewable articles. Sucharticles can provide nutrition and functional ingredients that areeffective to maintain or improve the animal's medical health. Thearticles can also provide tactile sensations, tastes, and aromas that,apart from any potential medical or nutritional benefit, improve thesubjective or psychological well-being of the animal.

Animals, such as pets, and their human care-givers can develop strongbonds of affection. A significant factor in development of suchaffection is provision by the human of food and pleasing stimuli to theanimals. Apart from recognition of a human as a merely functional sourceof food and pleasure, it is widely believed that animals are capable offorming psychological bonds with humans akin to those of inter-humanfriendship and love. Dogs, in particular, are believed to be capable offeeling and expressing intense emotional attachment for theircare-givers. Human care-givers also derive satisfaction from theircanine interactions.

Individuals who seek to cultivate affection with an animal canfacilitate its development by being a regular source of food andpleasing stimuli. In the context of pet care, it is beneficial for aproduct to be capable of satisfying multiple needs of an animal. Thus,it is beneficial if a dog chew, for example, can satisfy more than oneof a dog's urge to chew, a dog's desire to obtain an edible article, adog's desire to manipulate a plaything, and a dog's wish to share with(or at least obtain from) its care-giver a desirable object, whilesimultaneously providing a nutritional, veterinary, or hygienic benefitto the dog.

Described herein are animal chews that can be provided to an animal byan individual to enhance the health, happiness, and well-being of theanimal and to strengthen the emotional bond between the animal and onewho provides for its care.

Definitions

As used herein, each of the following terms has the meaning associatedwith it in this section.

A “target animal” simply refers to an animal of the type for which ananimal chew product described herein is intended to be used. By way ofexample, several of the animal chew products described herein areintended to be used by dogs and provided to dogs by their care-givers; adog is thus the target animal for such products.

An animal chew product or a portion thereof is “chewable” if it is hasrheological and other texture and organoleptic properties which tend topromote chewing upon the article by a target animal. Generally speaking,a chewable matrix will exhibit i) sufficient ductility that it is atleast slightly malleable when bitten by the target animal, ii)sufficient rigidity that it substantially retains its shapebefore-and-after a single bite by the animal, even though it may deformor degrade over the course of multiple bites, iii) sufficient integritythat it does not crumble when bitten by the animal the first time, eventhough it will crumble, break, or both over the course of multiplebites, and iv) sufficient palatability that the target animal is notdeterred by its taste from biting it multiple times. By contrast,“chewable” does not mean merely that an article can be chewed by ananimal (i.e., it does not mean merely that some portion of the articlewill fit within an animal's mouth sufficiently to permit engagement ofthe animal's teeth against the portion).

An “orally active” ingredient is one which exhibits a characteristicproperty, functionality, or activity after it has been delivered to theoral cavity of an animal.

A “temporally efficacious amount” of an orally active ingredient of ananimal chew described herein means an amount that can be expected toexhibit its characteristic property, functionality, or activity duringthe cumulative period of time during which a target animal can normallybe expected to chew upon the animal chew prior to consuming the animalchew.

A “resilient” portion of an animal chew means a portion that issignificantly less-quickly-consumable by chewing performed by a targetanimal than a consumable portion thereof.

A “chew-resistant” portion of an animal chew means a portion that iseven less-quickly consumable, such that substantially no part of achew-resistant portion would be consumed during a normal period ofchewing for the target animal.

A “flavorant” is a chemical compound or combination of compounds thatimparts a desired taste to a composition to which the flavorant isadded.

An “aromant” is a chemical compound or combination of compounds thatimparts a desired scent or odor to a composition to which the aromant isadded.

The “gelatinization temperature” or “gelatinization point” of a starchhas its art-accepted meaning, namely the temperature at which starchgranules begin to absorb water and lose birefringence. Qualitatively, itis the temperature at which starch chains become solvated by surroundingwater and available to interact with other compounds dissolved orsuspended in the water. It is recognized that different regions (e.g.,amylose-rich versus amylopectin-dense regions) of individual starchgranules can exhibit different gelatinization temperatures.

Detailed Description

Described herein are chewable articles intended to be provided toanimals (“animal chews”) for purposes including dental cleaning, breathfreshening, nutrition, administration to the animal of beneficialagents, satisfaction of the animal's urge to chew, and general enjoymentby the animal. The articles are believed to represent advances overpreviously-known animal chews in several respects.

Broadly speaking, the animal chews described herein have a form thatincludes a chewable matrix having a shape and dimensions selected tofacilitate mastication of individual animal chews by an animal. Theanimal chew can have a non-consumable portion (e.g., a non-consumablerope connecting two consumable matrix portions), but is preferablyconsumable in its entirety by the animal (like a traditional dough-basedbiscuit or rawhide chew).

The composition of the chewable matrix includes one or more ingredientsthat renders it appetizing to the animal (i.e., a flavorant or aromantthat tends to induce the animal to chew upon it). The matrix alsoincludes structural ingredients that confer a chewable texture to thematrix, meaning that it exhibits at least minimal deformability (i.e.,it is detectably compressible, ductile, or both, to the animal) andsufficient toughness (i.e., resilience, integrity, or both) to endurechewing by the animal for at least a couple of minutes, and preferablyfor substantially longer. In one embodiment, one or more flavorants andaromants is incorporated that renders the chew appetizing to an animal(e.g., a dog) but unappetizing to humans (e.g., a child).

Depending on the selected ingredients and characteristics of thechewable matrix, the animal chew will not be completely consumed by theanimal until it has been chewed for a period of minutes (e.g., 2-60minutes or longer, such as hours or even days). A consequence of thissustained chewability of the animal chew is that the chewable matrix canbe expected to remain in physical contact, in fluid communication, orboth, with the oral cavity of the animal for an extended period. Forthat reason, one or more ingredients that are included in the chewablematrix can be contacted with a surface or fluid in the animal's oralcavity for some or all of the chewing period (at least during periods ofactive chewing). Thus, the animal chews described herein can be used todeliver active ingredients to the oral cavity of the animal.

The animal chews described herein can be designed so that prolongedchewing by an animal will physically degrade the chewable matrixsufficiently that it can be broken up by the animal into crumbs or partssmaller than the original chew. The broken parts of the chewable matrixcan be further broken down or consumed by the animal, contributing toits nutrition and delivering an ingredient present in the chewablematrix to the stomach of the animal. The animal chews thus can be usedto deliver substantially any active agent known for oral delivery to theanimal, such as medicaments and nutrients. Furthermore, agents thatexert a beneficial effect upon an animal owing to mechanicalinteractions, rather than chemical ones, (e.g., abrasives that scour ananimal's teeth or a non-digestible fiber that enhances productivity andregularity of defecation by the animal) can be included in the chewablematrix.

The animal chews can be formulated to include in the chewable matrix aningredient that is beneficial to the health or hygiene of the animalwhen the chew is masticated by the animal. Hygiene-benefitingingredients include dentally efficacious ingredients such as abrasives,anti-plaque, and anti-tartar agents, and breath-freshening agents.Health-benefiting ingredients include veterinary pharmaceuticalingredients intended for topical administration in the mouth (e.g.,topical analgesics or antibiotics intended to treat an oral lesion) orfor systemic or gastrointestinal administration via the oral cavity(e.g., systemic analgesics or anti-helminthic agents). Pharmaceuticalingredients that are useful for facilitating or improving healing orrepair of gums (e.g., vitamin C and various known probiotic agents) areamong the ingredients that can be beneficially incorporated into thechews. Chews including such ingredients can be used as a mechanism forenhancing compliance by veterinary pharmaceutical subjects.

The animal chews can be made in a wide variety of shapes and sizes.Shapes can be selected to be pleasing to the animal or to itscare-giver. Significantly, shapes of the chews, and especially of thechewable matrix, can be selected to enhance the functionality of thechew. Chews intended for dental cleaning effected by abrasion of theanimal's teeth against the chewable matrix can be formed with shapesselected to enhance contact between the chew and non-biting portions ofthe animals' teeth. Chews intended for delivery of an agent with anunpleasant taste can be formed as a hollow chewable shape in which theagent is contained within the hollow in a softer, readily-swallowedcomposition. The shape selected for the chew can also facilitategrasping and handling of the chew by the animal, such as a twisted shapethat will not lie flat against a flat surface such as a floor. Shapescan also be selected to be whimsical (e.g., having the appearance of asnake or a pretzel) or to simulate the shape of an alternative chewingarticle (e.g., a bone).

Compositions and properties of, desirable shapes and uses for, andmethods of making the animal chews described herein are described insections below.

Composition of the Animal Chew

The composition of the animal chew (and, in particular, the chewablematrix thereof) is not critical. Animal chews having the shapes andproperties described herein can be manufactured from substantially anymaterial capable of assuming and retaining the shapes and exhibiting theproperties described herein. Such materials should result in an animalchew product having a chewable matrix that is appealing to the targetanimal and which can be chewed by the target animal for at least oneminute or longer without being substantially completely degraded. Thechewable matrix should also not yield sharp-edged or acutely-pointedfragments when chewed by the animal (in order to avoid injury to theanimal from chewing of such fragments). The chewable matrix preferablycan be degraded upon chewing by the animal to yield relatively blunt“crumbs” of a size amenable to swallowing by the animal (potentiallyafter further chewing of larger fragments). The matrix should besufficiently digestible that crumbs that are swallowed by the animal canbe degraded sufficiently by digestion in the animal's gut that thecrumbs do not present a substantial risk of intestinal blockage (e.g.,upon swelling of swallowed crumbs induced by absorption of liquid withinthe gut) or other injury.

The material used to make the chewable matrix is preferably palatable tothe animal, and is more preferably perceived by the animal as beingappetizing. By way of example, the chewable matrix material can includea foodstuff (e.g., a meat or grain meal) that is generally perceived asappetizing by the animal, a flavorant, an aromant, or a combination ofthese, in an amount that induces the animal to chew upon the matrix whenit is presented with the chew. Texture (e.g., compressibility orfrangibility), taste (e.g., sweetness), or both conferred to the matrixby a saccharidic processing aid included therein can also contribute tothe palatability of the chewable matrix.

The materials and methods used to make the chewable matrix should beselected to yield a matrix that, in addition to being chewable, isdigestible by the animal to which the chew described herein is given.Digestibility of the matrix is desirable for portions of the matrix thatmay be dissolved or suspended in the animal's saliva, for small flecksor crumbs of the matrix that are swallowed, and for larger chunks of thematrix that may be swallowed before being chewed completely to crumbs.Digestibility of the matrix can reduce the likelihood that swallowedmaterials will be regurgitated by the animal, cause stomach discomfortor upset to the animal, and adversely affect stool formation ordefecatory function.

Digestibility of the chewable matrix can be assessed by observinganimals who consume the chews. Alternatively, digestibility can beassessed in model systems, such as a stirred beaker filled withsimulated animal gastric fluid at the body temperature of the animal.The matrix is preferably sufficiently digestible that crumbs (e.g., ca.5 millimeter-diameter pellets prepared by grinding or crushing thematrix) are substantially reduced to their insoluble components (e.g.,insoluble fiber, ash, and insoluble minerals) within at least about 2hours of stirring in simulated dog gastric fluid at 101 degreesFahrenheit, and preferably within at least about 60, 45, 30, 20, 10, 5,or 2 minutes of such treatment. Alternatively, digestibility of thechewable matrix can be assessed using an in vitro model system in whichthe matrix (crumbled or ground) is mixed with a fluid containingdigestive enzymes (e.g., pancreatin) representative of those that occurin the digestive tract of animals (e.g., dogs) for which the chews areintended. In a third alternative, ground or broken-up pieces of theanimal chew can be contacted with a simulated gastric fluid and thencontacted with a simulated (digestive enzyme-containing) intestinalfluid to model passage through the gut of an animal. In each of thesetest systems, the pH, ionic strength, temperature, and enzyme content ofthe fluid can be selected to approximate those present in gastric andintestinal fluids of the target animal.

Digestibility of the chewable matrix is influenced by the composition ofthe matrix (generally, more digestible components will yield a moredigestible matrix, as will a matrix that can be more easily mechanicallybroken up by an animal). Digestibility of the matrix is also influencedby the degree to which the melt used to form the matrix is mechanicallyworked (e.g., the mechanical energy input conferred to the melt by theextruder), by the degree to which the melt is heated or cooked, and thewater (or other liquid) content of the melt (greater liquid content candecrease digestibility, presumably by ‘lubricating’ the melt componentsand inhibiting energy transfer through mechanical working thereof).Without being bound by any particular theory of operation, the degree ofstarch gelatinization achieved during melt extrusion is believed toinfluence the digestibility of the matrix. Starch occurs naturally in acondensed, largely crystalline form that is more resistant to digestionby animals than gelatinized forms of the same starch. Heating andmechanical working of the starch in the presence of sufficient hydrationcan reduce the crystalline nature of a starch and increase the fractionof starch that is gelatinized.

Highly crystalline starch tends to exhibit low digestibility, mostlikely because crystalline starch regions are not vulnerable toenzymatic cleavage or other starch-lytic agents in fluids. Highlygelatinized starch tends to be highly digestible to soluble cleavageproducts in the gut. In order to enhance digestibility of the animalchew described herein, it can be desirable to heat and/or mechanicallywork (i.e., input mechanical energy into) the starch-containing meltsufficiently that at least about 50% (on a weight basis) of the starchpresent in the melt assumes a gelatinized form. Preferably, suchheating, working, or both, achieves a starch gelatinization level in themelt of at least about 80%.

Even though the identity of the chewable matrix material is notcritical, a variety of compositions are described herein of which thechewable matrix of the animal chew is preferably made. Thesecompositions preferably have one or more of the followingcharacteristics:

i) a relatively high ratio of starch-to-protein (e.g., starch beingpresent in a two- to five-fold excess relative to protein, on a weightbasis);

ii) in the starch fraction, an excess of amylose to amylopectin (e.g., a1.5- to three-fold excess of amylose relative to amylopectin, on aweight basis);

iii) inclusion of one or both of an acid-thinned starch and alow-melting starch (e.g., a high-amylose starch, such as sago palmstarch);

iv) a low fat content (e.g., a fat content not greater than 5 wt % ofthe chewable matrix, and preferably not greater than 3 wt %);

v) a substantial content (e.g., about 2-6 wt % of the chewable matrix)of a dentally-efficacious abrasive ingredient, such as one or both of ahard particulate agent and a fiber; and

vi) inclusion of a saccharidic processing aid (e.g., 0.5-10 wt % of thematrix).

One embodiment of a suitable chewable matrix has a composition thatincludes about 9-17 wt % protein, about 40-50 wt % starch, water (and,optionally, a humectants) in amounts sufficient to confer chewableplasticity to the chewable matrix after it is melted and formed, and atemporally efficacious amount of an orally active ingredient. Thebalance of this formula can be substantially any other ingredient thatdoes not materially affect the properties of the ingredients describedherein. For example, those other ingredients can include flavorants,aromants, colorants, vitamins, minerals, nutrients, fillers, andpreservatives. The ingredients of this matrix formula can be combined,heated above the gelling point of the starch (or at least a portion ofthe starch), and thereafter shaped into the chewable article. Chewableplasticity of the matrix can be enhanced by including one or moresaccharidic processing aids therein. Chewable articles thus formed canexhibit the properties disclosed herein.

The identities and proportions of these ingredients are not critical.They can be as specified herein. A skilled artisan will recognizepermissible variations in ingredient identities and proportions that canbe made for chewable matrices that exhibit the properties disclosedherein.

An important consideration in selecting the ingredients and theirproportions for the chewable matrix is that the animal chew formedtherefrom (i.e., after heating the mixed ingredients above thegelatinization point of at least some of the starch, forming and shapingof the chew, and cooling to approximately 20 degrees Celsius), shouldexhibit sufficient friability that substantially all of the consumableportion of the chew can be consumed by the animal in not more than fourhours of composite chewing time (i.e., the summed duration of alldiscrete chewing periods). Although this characteristic will depend onthe size and shape of the chew that is selected, the friability of thechew can be selected so that the matrix of an individual can be consumedin less time, such as in two hours, one hour, 30, 20, 10, 5, 4, 3, or 2minutes, for example, and preferably more than 30 or 60 seconds.

Another important consideration in selecting the ingredients and theirproportions is that the animal chew formed therefrom should exhibitsufficient integrity that a substantial portion of the consumableportion of the chew will remain non-consumed by the animal after atleast one minute of composite chewing time. Although this characteristicwill depend on the size and shape of the chew that is selected, theintegrity of the chew can be selected so that the matrix of anindividual will remain non-consumed for a greater period of time, suchas for 2, 5, 10, 20, 30, 60, 90, or 120 minutes, for example.

The amount of time required for an animal to consume a chew describedherein by chewing it will depend on a number of factors that can beselected to achieve a desired chew time. Such factors include, forexample, the moisture content of the chew, the amount of pressureapplied to the chew during its manufacture, the temperature to which thechew material is heated during manufacture and the amount of time it ismaintained at that temperature, the degree to which gas pockets areremoved from the chew material during processing (e.g., by applicationof a vacuum to the molten chew material or by compression), the contentof starch and other ‘chewy’ materials incorporated into the material,the amount of minerals (e.g., gypsum) in the material, and the shape andsize of the chew. Different animals will also exhibit different chewtimes for the same treat (e.g., a large, healthy dog will generallyconsume the same chew more quickly than a small, unhealthy dog).

Another important consideration in selecting the ingredients and theirproportions is how resistant the chew is to fracture upon chewing. It isdesirable that the chew ultimately fracture (preferably into relativelysmall crumbs), and that the pieces be consumable by the animal. However,in order to increase the period of time during which adentally-efficacious ingredient in the matrix can exert its effects uponthe animal's teeth, it is desirable that the chew be sufficiently toughand resilient that the animal must bite the product numerous timesbefore it is reduced to consumable pieces. By way of example, it can bedesirable that the chewable matrix exhibits sufficient rigidity that thechewable matrix does not substantially fracture (or, at least, is notreduced to pieces that will be routinely swallowed by the animal) untilit has been chewed at least about 25 times by the animal. Theingredients and proportions can be selected so that a greater or lessernumber of bites is necessary to fracture or crumble it, such as about10, about 100, about 500, or about 2000 bites.

Yet another important consideration in selecting the ingredients andtheir proportions is that the animal chew formed therefrom shouldexhibit sufficient ductility that the animal finds chewing of the matrixto be desirable. By way of example, the chew should be formed so thatthe animal is able to leave a visible indentation in the surface of thechewable matrix upon biting the chew with a force less than the maximumbite force that the animal can exert upon the chew. For animals (e.g.,aged animals) that can be anticipated to have more fragile teeth thananother, healthier animal of the same species and breed, a more ductilechew can be desirable for the aged animal than for the healthier animal.

An important consideration, related to chew time, in selecting theingredients and their proportions is that residence time of the animalchew in the mouth of the animal. It is desirable that certainingredients of the chew (e.g., anti-tartar agents and veterinarypharmaceutical agents) be available in the animal's oral cavity (e.g.,in its saliva) for a time sufficient to exert a desired effect. Forexample, it is desirable that teeth of an animal be contacted with ananti-tartar agents for at least 30 to 60 seconds, and preferably 1, 2,3, 4, or 5 or more minutes. Similarly, pharmaceutical agents intended toact within the oral cavity of the animal typically must be present for asufficient time (the time depending on the concentration of the agent)to exert a desired physiological or pharmacological effect. The chewtime and the appetizing character of the animal chew described hereinshould be sufficient to achieve an oral residence time of the chewsufficient to permit the action of any such agent(s) included in thecomposition of the chew.

Animal chews can be made as described herein so that they exhibit one ormore (and preferably all) of the friability, integrity,resistance-to-fracture, and ductility characteristics described herein.

Starch

The animal chew preferably includes about 40-50 wt % starch in thechewable matrix thereof. The type and source of the starch are notcritical, so long as the other properties of the animal chew areexhibited by the formulation used. To the extent the starch content ofthe formulation of the chewable matrix is altered beyond this range,starch derivatives and compounds which exhibit starch-like propertiescan be used. By way of example, dextrins, pectins, starch hydrolysates,and other natural polysaccharides can be used in place of at least asmall proportion of the starch (e.g., 0-10 wt % of the chewable matrixformulation), so long as the replacement exhibits properties like thoseof the starch it replaces. Furthermore, pregelatinized starches can beincluded in the materials used to form the matrix.

Modified starches also can be used in the formulation as a part of theoverall starch content of the formulation. By way of example, thechewable matrix composition can include no, 2 wt %, or 6 wt %acid-thinned starch, no, 2 wt %, or 6 wt % high-amylose starch, or acombination of these two.

The source from which the starch is obtained is not critical, so long asthe starch is suitable for consumption by the target animal.Considerations of availability, cost, and processability of the starchsource can influence selection of an appropriate source. Whole grains,broken grains, flours, roots, and tubers can be used as sources for thestarch in the chewable matrix. Examples of suitable starch sourcesinclude wheat, rice, corn, potatoes, cassava. These and other sources ofstarch can be used for the compositions described herein.

As is known in the field of starch chemistry, many combinations ofstarches can be used to achieve the desired properties of the matrix,and a skilled artisan in the field understands that a certain amount ofempirical experimentation and observation normally accompaniesdevelopment and optimization of starch-containing compositions. Suchexperimentation is to be expected in connection with development of thechewable matrix compositions described herein. By way of example, it canbe seen from the graphs in FIG. 19, that the identities and proportionsof starches present in the chewable matrix can significantly influencethe properties of the matrix, including its setting time (i.e., time tohardening after melting during processing), hardness, and moistureretention.

The starch content of the chewable matrix is preferably selected so thatthe matrix contains 10-20 wt % amylose and about 40-30 wt % amylopectin.Selection of starches having known amylose and amylopectin content isconventional in the art. By way of example, waxy corn, rice, and sorghumstarch are known to be composed of almost 100% amylopectin and can beused to boost the amylopectin content of a starch-containing matrix. Byway of converse example, many high amylose content starches (e.g.,high-amylose corn starches having an amylose content of 75% or more) areknown, and these can be used to boost the amylose content of astarch-containing matrix. Amylose and amylopectin proportions can beobtained by selecting a starting material having starch in the selectedproportion, by mixing starches from various starting materials, or bysupplementing starch from natural sources with modified starches such asacid-thinned or high-amylose starches. By way of example, the matrix cancontain 30-40 wt % starch obtained from rice in combination with 4-8 wt% starch that is present in a form selected from the group consisting ofacid-thinned starches, dextrins, and combinations of these. By way of analternate example, the matrix can contain 30-40 wt % starch obtainedfrom broken rice grains (i.e., brewer's rice) in combination with 1-7 wt% starch obtained from sago. It is desirable that the overall starchcontent be at least about 40 wt %, by which it is meant that the overallstarch content can be at least somewhat lower, such as not less than 35wt %, and preferably at least 37, 37.5, or 38 wt % starch.

Without being bound by any particular theory of operation, it isbelieved that gelatinization of starch in the chewable matrix during itsprocessing is responsible for the workability and moldability of thematrix material. Preferably, at least about 50 wt % of the starch in thechewable matrix is gelatinized during processing, and it is consideredeven more preferable that about 80 wt % of the starch in the chewablematrix be gelatinized during processing.

Polysaccharides other than starches (e.g., pectins, agars, carageenans,and vegetable gums such as guar gums) can be included in the matrix.Inclusion of polysaccharides in a chewable matrix can, generallyspeaking, be expected to increase the rigidity, integrity, and chew timeof the chewable matrix, relative to the same matrix lacking thepolysaccharide.

Protein

The source of protein used for the chewable medium is not critical and askilled artisan is able to utilize protein obtained from any of a widevariety of sources to form the chewable matrix of the animal chewsdescribed herein. The protein source can, for example, be relativelypure and well-characterized, such as casein and albumin preparationsmade from milk and eggs, respectively, or they can be less pure andwell-characterized mixtures, such as protein-containing waste (orby-product) streams from meat-processing operations. The protein shouldbe suitable for consumption by the target animal (at least followingprocessing of the protein into the chewable matrix of the formed animalchew), and is preferably digestible by the target animal. Preferably,the protein source is one that is considered appetizing by the targetanimal, such as chicken, beef, or pork by-products for animal chewsintended for dogs. Protein isolates, such as those derived from animaltissues, eggs, or plants can be used. Suitable vegetable-derivedproteins such as glutens can be included, and are preferred for animalchews designed to be free of animal products. Use of such appetizingprotein sources can reduce or eliminate the need to add flavorants,aromants, or colorants to the matrix for palatability purposes.

The protein of the chewable matrix should be substantially miscible withthe starches of the matrix, at least in its melted state, and shouldform a substantially homogenous matrix when thoroughly mixed with thestarches and other ingredients, melted, and shaped into a chew. Withoutbeing bound by any particular theory of operation, it is believed thatprotein present with starches and water in the melt used to form thechewable matrix in the processes described herein substantiallyintermixes with the starches to form a hybrid starch-protein structurethat contributes, at least somewhat to the chewable matrix propertiesdescribed herein.

A sufficient amount of the protein source should be included in thechewable matrix to confer a protein content to the matrix of about 9-17wt % in its finished form. The precise amount of protein included in thechewable matrix is not critical. Also not critical is whether thisprotein content is derived from a single source or by combination of theprotein contents of multiple ingredients of the matrix.

In one embodiment, the matrix lacks any ingredient derived from ananimal source, but still contains 9-17 wt % protein, the protein beingderived from one or more plant sources instead.

It is known that inclusion of protein-containing ingredients incompositions such as the chewable matrix of the animal chews describedherein can affect the properties of the matrix, such as those propertiesthat are described herein. The protein-containing ingredients should beselected together with the other ingredients of the chewable matrix soas to yield animal chews having the desired properties described herein.Formulation of such compositions, including empirical experimentationand observation of formula variations is within the level of skill of anordinary designer in this field, in light of the teachings providedherein.

Water and Humectants

The chewable matrix should include about 12-18 wt % water in itsfinished form. The matrix preferably includes about 16 wt % water in itsfinal form. If the matrix includes a saccharidic processing aid, theamount of water used to form the matrix can be lowered, and a lowerfinal water content (e.g., 11.5-14.5 wt %) can be used. By way ofexample, a matrix that includes about 5 wt % of a saccharidic processingaid such as a dextrin can include about 13 wt % water while stillretaining favorable processing and chewability characteristics. Duringprocessing, the matrix can contain a greater water content (e.g., toenhance processability of the matrix), but the final water content ofthe animal chew should be brought within this range in the finishedchew, for example by drying (at ambient or elevated temperature) or byvacuum extraction. The source and purity of the water is not critical,so long as the water is suitable for consumption by the target animal,at least following processing of the chewable matrix into an animalchew.

Without being bound by any particular theory of operation, it isbelieved that water present in the matrix hydrates starches and proteinsthat are present therein, lubricates or facilitates movement of starchand protein chains, and significantly contributes to the physicalproperties of the matrix.

Several properties, such as ductility and water retention, of thechewable matrix can be improved by including a humectant in the matrix.When a humectant is used in the chewable matrix, it (or a combination ofhumectants) should be present in an amount not greater than about 12 wt%, and preferably in the range from about 2-10 wt %.

Numerous humectants are known in the art and substantially any humectantcan be used, so long as it is chemically compatible with the othercomponents of the chewable matrix and is suitable for consumption by thetarget animal. Examples of humectants suitable for use in animal chewsfor dogs include glycerol and propylene glycol.

Processing Aids

Doughs, plastic materials, and other highly viscous semi-solid materialsrequire processing equipment that can accommodate the physicalproperties of such materials. Known difficulties in handling thesematerials include stickiness and resistance to flow. Resistance to flowcan hamper transfer, molding, and shaping operations, as well asrequiring greater power inputs to achieve them. Upon mixing and heatingof its components, the chewable matrix material used to form the chewsdescribed herein tends to be a highly viscous dough or plastic-likematerial. If the resistance to flow of the chewable matrix could bereduced, the amount of power required to make the chews described hereincould be lessened and limitations on molding and shaping operationscould be lessened.

It has been discovered that a variety of monosaccharides, disaccharides,and short (i.e., 3-9 saccharide unit) oligosaccharides can be used asprocessing aids to reduce the resistance to flow of the chewable matrixdescribed herein during its processing. These agents are collectivelyreferred to herein as “saccharidic processing aids.” Inclusion of thesesaccharidic processing aids in the chewable matrix improves theflowability of the matrix in the chew-forming and shaping operationsdescribed herein. The saccharidic processing aids also appear to act asa lubricant.

The amount of the saccharidic processing aid that is included in thematrix is not critical, but should be selected to provide at least anoticeable improvement in fluid properties of the chewable matrix duringits processing. The amount of the saccharidic processing aid should not,however, be so high as to eliminate the other properties of the chewablematrix described herein. Moreover, because some saccharidic processingaids (e.g., sucrose or dextrose) can be detrimental to oral or dentalhygiene of animals, it can be desirable to limit the quantities in whichsuch agents are used in the matrix. By way of example, for thecompositions described herein in Example 2, incorporation of asaccharidic processing aid in an amount of about 0.5-10 wt % (e.g., 0.5,1, 2, 3, 4, or 5 wt %) of the composition (e.g., in addition to thematerials listed in the Example, or in place of one or more ingredients,such as water) can yield beneficial improvements in matrixprocessability.

A saccharidic processing aid can improve fluidity of the matrix duringprocessing.

Fluidization of the matrix is also provided by water present in thematrix. In some embodiments that are described herein, water is removedfrom the formed chew (e.g., by drying in an oven). Because thesaccharidic processing aids described herein can provide some of thefunctionality that water provides to the matrix, inclusion of asaccharidic processing aid permits the water content of the matrix to bereduced, with the result that less drying of the formed chew can berequired in order to attain a desired final water content.

Examples of suitable saccharidic processing aids include substantiallyall edible monosaccharides, disaccharides, and oligosaccharides having3-9 (identical or not) saccharide units. Specific examples includesimple sugars and sugar alcohols such as dextrose, fructose, sucrose,mannitol, sorbitol, xylitol, and dextrins such as maltodextrins.Suitable saccharidic processing aids include mono-, di-, andoligo-saccharides that are derived from starches, including dextrose,dextrins, and maltodextrins, for example. Oligosaccharides derived fromstarch can contribute both as “starches” (as defined in thisspecification) and as saccharridic processing aids. Thus, by way ofexample, a matrix described herein can include as little as about 40 wt% of various starches, including substantial amounts (e.g., 0.5-10 wt %)of one or more saccharidic processing aids. Mixtures of more than onesaccharidic processing aid can be used.

In addition to their effects on the texture of a matrix in which theyare incorporated saccharidic processing aids can be selected, at leastin part, based on the taste which they can confer to the matrix. Varioussaccharides are known to confer certain taste sensations (e.g.,sweetness and flavor) to formulations in which they occur, and selectionof saccharidic processing aids which improve or complement other flavorsin the matrix described herein (especially from the point of view of thespecies for which it is intended) can be beneficial.

Certain embodiments of the chews described herein are intended toimprove oral hygiene or oral or dental health of animals to which thechews are provided. For such chews, it can be beneficial to usesaccharidic processing aids that are not significantly detrimental tothe beneficial oral or dental characteristics of the chew. By way ofexample, some saccharidic processing aids (e.g., sucrose) are known topromote formation of plaque, tartar, caries, or tooth decay in animals,and use of such saccharidic processing aids should be minimized oravoided in chews intended to promote oral or dental health. Manynon-cariogenic saccharides are known, and most or all of them can beused in place of cariogenic saccharides for the purposes describedherein.

When used as a processing aid, a saccharide can be included in theinitial mixture of ingredients that is combined to form the chewablematrix. Alternatively, the saccharidic processing aid can be added(e.g., in dry form or in the form of a concentrated solution orsuspension) during thermal processing of the already-formed matrix. Byway of example, the saccharidic processing aid can be combined withmatrix at or near the outlet of an extruder in which the othercomponents of the matrix are mixed and heated. The saccharidicprocessing aid must generally be incorporated into the matrix in orderto influence the fluidity and processability of the matrix. However, thesaccharidic processing aid can be added to only the portion of thematrix nearest the outer surface of a chew if only the digestibilityenhancement described below is desired.

An additional benefit of including a saccharidic processing aid in thecomposition is that it can reduce degradation of other ingredients ofthe composition. For example, ingredients which tend to hydrolyze uponexposure to high temperatures (e.g., temperature levels in an extruderbarrel) can exhibit decreased degradation either by exposure to lowertemperatures (enabled by use of a saccharidic processing aid) or byshorter exposure to the same temperature (e.g., resulting from fasterthroughput enabled by use of a saccharidic processing aid). Further byway of example, ingredients which tend to degrade upon exposure toenergetic or vigorous physical processing (e.g., physical forces exertedupon mixing or extruding the composition) can exhibit lower degradationeither by exposure to lesser processing (e.g., either lower physicalforces attributable to lubricating properties of a saccharidicprocessing aid or faster throughput enabled by use of a saccharidicprocessing aid).

In addition to improving the mechanical processability of the chewablematrix, a saccharidic processing aid added to the matrix can alsoenhance the digestibility of the formed matrix by an animal whichswallows it. Without being bound by any particular theory of operation,the saccharidic processing aid is believed to facilitate absorption ofwater and other components of digestive fluids (e.g., acid and enzymes)into the chewable matrix. Such absorption can hasten the rate at whichthe matrix is digested upon ingestion by an animal. Such absorption canalso enhance absorption of saliva into the matrix during chewing,facilitating fracture and consumption of the matrix by the animal.

Other Ingredients

The chewable matrix of the animal chews described herein can containingredients other than starches, proteins, water, and humectants. Suchingredients can include fillers that do not materially affect anyrelevant property of the chew, such as ingredients which provide bulkwithout substantially affecting the hardness, ductility, or resilienceof the chew.

The chewable matrix can include ingredients that affect thepalatability, nutritiousness, shelf-life, or appearance of the animalchew without substantially affecting its physical properties (e.g.,without substantially affecting the hardness, ductility, or resilienceof the chew). Examples of such ingredients include vitamins, minerals,other nutrients, flavorants, aromants, colorants, and preservatives. Tothe extent that any such ingredient that is included in the chewablematrix affects a desired physical property of the animal chew, thecontent of one or more of starches, proteins, water, and humectants inthe formulation can be adjusted to account for such effects and tomaintain the properties of the chewable matrix within desired ranges.

Any vitamins, minerals, or other nutrients included in the chewablematrix should be selected to be present in an amount or concentrationsuitable for ingestion by the target animal. A wide variety of suchnutrients are known for animals, and their selection and dosing forconsumable compositions such as the animal chews described herein iswithin the ken of a skilled artisan in this field.

Flavorants, aromants, colorants, and preservatives should be selectedand formulated to be present in amounts that are sufficient to achievetheir respective functionalities, but also should be selected both to besuitable for consumption by the target animal and so that they do notleave undesirable stains, aromas, or other residue on surfaces contactedby a partially-chewed animal chew. Preservatives, for example, can beselected to inhibit microbial growth in or other spoilage of packagedanimal chews during storage, or they can be selected to inhibitmicrobial growth upon an animal chew that has been gnawed, but notcompletely consumed, by an animal so as to reduce the likelihood ofillness or digestive upset attributable to growth that might otherwiseoccur on or in a partially-consumed gnawed during the period betweengnawing sessions.

If ingredients that are sensitive to thermal degradation duringprocessing (e.g., hydrolysis) are included in the chewable matrix, theextent of degradation can be modulated by altering processing of thematrix. Of course, if the extent of degradation is predictable and thedegradation by-products are not harmful or undesirable, the amount ofthe sensitive ingredient can simply be increased to account forpredictable degradation. By way of example, when aqueous suspensions ofsodium tripolyphosphate (STPP) are subjected to high temperatures, somehydrolysis of STPP can occur, especially when the suspension has arelatively high water activity. Hydrolysis of STPP can be reduced byreducing the process temperature of the mixture (e.g., in an extrusionor drying step), by decreasing the period of time that the mixture ismaintained at a temperature at which STPP degrades, by decreasing thewater activity of the mixture (e.g., by adding salts or water-bindingingredients), or by some combination of these.

Orally Active Ingredients

A particularly important class of ingredients that can be included on orin the chewable matrix of the animal chews described herein are agentswhich exert a physiological effect upon the target animal when it gnawsupon the animal chew. Examples of orally active ingredients that can beincluded are dental prophylactic ingredients, breath agents,anti-halitosis agents (including both those which inhibit or preventonset of halitosis and those which reduce the intensity of or eliminatehalitosis) pharmaceutical agents, and combinations of these. Suchingredients can be dispersed substantially homogenously in the chewablematrix, contained within a selected portion of the matrix, containedwithin a cavity or hollow within the matrix, coated on the matrix, orsome combination of these. Such ingredients can also be disposed on orwithin a portion of the animal chew other than the chewable matrix(e.g., coating, or contained within a hollow of a non-consumable portionof the chew), so that the target animal is exposed to the agent upongnawing the chewable matrix of the chew.

Active agents included with the chewable matrix can exert theiractivities in various ways, and the expected or desired mode of actionof such agents can influence where (i.e., on or within the matrix) andhow the agents are disposed in the chew.

Agents expected or intended to exert their functionality by way ofdirect contact with the teeth of the target animal should, of course, bedisposed within the chew at a location at which direct contact betweenthe teeth and the chew is anticipated, such as on the surface of,throughout the chewable matrix, or both.

Similarly, agents expected or intended to exert their functionality byway of suspension or dissolution in an oral fluid (e.g., saliva ormucus) of the target animal should be disposed at a location on or inthe chew that is anticipated to be placed in fluid communication withsuch oral fluids upon mastication of the chew. By way of example, agentsactive in an oral fluid can be situated on the surface of the chewablematrix, on a surface of the chew other than the chewable matrix, withinthe chewable matrix (i.e., throughout the matrix or within a cavity orhollow therein), or within a hollow in a compressible portion of anon-consumable portion of the chew (i.e., so that the agent is expelledfrom the hollow upon compression of the non-consumable portion inducedby biting by the target animal).

Active agents intended to be carried by a fluid during mastication canbe further subdivided into those agents intended to exert their effectsubstantially only with the oral cavity of the target animal (e.g.,water-soluble dental prophylactic agents, such as fluoride oranti-tartar agents, or pharmaceutical agents intended for topicaldelivery to oral sites of action) and those agents intended for broadersystemic or gastrointestinal (GI) delivery to the target animal. Theformer, orally-acting agents are preferably disposed within the chew ata location at which the agent will contact an oral fluid over aprolonged period of time (i.e., during most or all of the time while thechew is masticated), so as to effect sustained delivery of the agent tooral sites. The latter, systemically- or GI-acting agents can bedisposed more flexibly; so long as the desired dose is administeredduring mastication of the article, it does not matter whether the doseis delivered as a relatively short-duration bolus (e.g., if the agent isdisposed in a soluble coating of the chew) or over a longer duration(e.g., if the agent is disposed throughout the chewable matrix andreleased as it is chewed).

Dental Prophylactic Ingredients

An important class of orally-active agents that can be administeredusing the animal chew described herein is dental prophylacticingredients. Examples of dental prophylactic ingredients includeabrasives (for scouring tooth surfaces to remove plaque, tartar, andother materials therefrom), anti-tartar agents, fluoride and othertooth-strengthening agents, surfactants and other surface-cleaningagents, and pharmaceutical agents for topical delivery to teeth and gums(e.g., antimicrobial agents, anti-inflammatory agents, and other agentseffective to treat or prevent gingivitis).

Abrasives

Use of abrasives for dental cleaning purposes is well known, andsubstantially any abrasive known for dental cleaning purposes can beincorporated into the animal chews. The identity of the abrasive is notcritical. Suitable abrasives include both particulate and fibrousabrasives. If the abrasive is disposed in a consumable portion of thechew (e.g., on or in the chewable matrix) or if the abrasive is attachedto a non-consumable portion in a releasable manner (i.e., so thatingestion of the abrasive by the target animal is anticipated), then theabrasive should be selected to be one that is substantially safe forconsumption by the target animal. A large variety of such abrasives areknown, including abrasives commonly included in human toothpastes otheranimal dentifrices.

Suitable particulate abrasives include, for example, mineral powderssuch as gypsum, titanium dioxide, silica, calcium carbonate, andcombinations of these. Other acceptable particulate abrasives includenaturally-occurring and synthetic polymer particles, such as particulatecelluloses and ground or shredded plant materials.

Abrasive particles should be selected to be compatible with andnon-irritating to the oral and GI tissues of the target animal, inaddition to being suitable for ingestion. In one embodiment, abrasiveparticles are selected that exert an abrasive effect within the oralcavity and that are capable of partial or total dissolution with a fluidin the GI tract of the target animal so as to provide a dietary sourceof a mineral for the animal. By way of example, calcium carbonate andgypsum each act as abrasive particles at the relatively neutral pH ofthe oral cavity, but can partially dissolve at the acidic pH within thestomach of mammals, yielding soluble calcium ions that can be absorbedby the body. For animals susceptible to development of solid mineralbodies within their bladder, kidney, pancreas, gall bladder, or otherorgan(s), abrasive particles can be selected that will not contribute tosuch development by avoiding minerals which so contribute, and these areknown in the art.

Suitable fibrous abrasives include plant fibers, such as cotton fibersand grain brans (e.g., rice hulls, coconut husk, and shredded wheatbran). Fibrous abrasives also include synthetic fibers (e.g., nylon orrayon fibers) and semi-synthetic fibers (e.g., cellulose fibers isolatedfrom a plant material). Fibers derived from animals (e.g., collagenfibers derived from tendons, ligaments, and other food animal wastes)can also be used.

Abrasive fibers should be selected to be compatible with ingestion bythe target animal. Fibers can be selected that are digestible by theanimal, partially digestible, or substantially indigestible. Whensubstantially indigestible abrasive fibers are used in the animal chew,the type and amount of the fibers and their anticipated rate of releasefrom the chew, taken together with other chew components that can beexpected to contribute to stool formation, should be selected to avoidaccumulation to an undesirable degree within the GI tract of the targetanimals, so as to avoid complications such as intestinal blockage.Fibrous materials that are, for example, too large in size to be safelyfed to small target animals can be processed (e.g., by grinding,shredding, cutting, or chemical or enzymatic degradation) to render themsafe for use herein. Such considerations are within the ken of asskilled artisan in this field. In the final product, total dietary fibercontents in the range 15-25 wt % are desirable, and this amount can bedivided among soluble insoluble fiber fractions. Some (e.g., ⅓ to ½),all, or none of fiber can be present as crude fiber (i.e., cellulose andlignin).

Abrasives should be disposed on or in a portion of the chew that will becontacted by the target animal's teeth for an extended period, mostpreferably in at least the chewable matrix of the chew. Abrasives exerttheir cleaning effect by way of mechanical abrasion between the teethand the abrasive. Accordingly, the abrasive should be relatively rigidlyfixed on or at a portion of the chew, so as to provide the mechanicalsupport to the abrasive necessary for it to retain a fixed positionwhile a tooth surface scrapes against an abrasive particle or fiber.

Another concern in selection of abrasive particles or fibers is theeffect that such particles may exert as wear upon processing machinery.Mineral particles, for example, having a hardness greater than thehardness of a processing part against which flow of particle-containingmaterial is anticipated can be expected to accelerate wear of themachinery. Selection of abrasives and process machinery constructionshould therefore be considered together.

The amount of abrasive included within the chew is not critical, andgreater abrasive action will generally be expected with increasingamount of abrasive. The amount of abrasive should also be selected toachieve the desired degree of dental cleaning, taking into account themethod and duration of chewing that the target animal can be expected toperform upon the chew. Furthermore, the effect of the abrasive upon theproperties of the chew (e.g., the hardness, ductility, and resilience ofthe chewable matrix, if the abrasive is included therein) should betaken into account when selecting the identity and amount of theabrasive(s).

Generally speaking, one or more abrasives is preferably included withinthe chewable matrix of the chew. Abrasive contents up to about 10 wt %for the chewable matrix are generally considered acceptable, and thiscontent may be divided between two or more abrasives, each of which maybe particulate or fibrous. By way of example, the chewable matrix mayinclude 5-7 wt % of a fibrous abrasive and 0-3 wt % of a particulateabrasive. By way of further examples, the chewable matrix may includeabout 5 wt % of a particulate abrasive and 0-5% of a fibrous abrasive.

A skilled artisan is able to determine, at least empirically, anappropriate amount of abrasive to include in the compositions describedherein in order to achieve a desired degree of dental cleaning. By wayof example, it is desirable that a degree of dental cleaning equivalentto that achieved by brushing a target animal's teeth every other day,every week, or every other week (i.e., using a traditional brush and ananimal-appropriate dentifrice) can be achieved by daily provision to thetarget animal of an animal chew described herein. More preferably, thedegree of dental cleaning thus achieved is equivalent to that achievedby daily brushing of the animal's teeth. Abrasive cleaning actioneffected by abrasives in the chew can, of course, be combined orsupplemented with chemically-based cleaning action effected, forexample, by polyphosphates or other metal-chelating anti-tartar agentsincluded in the chew formulation.

The degree of dental cleaning (whether achieved by brushing or bychewing a chew described herein) of an animal can be quantified in anyof several ways. Such quantification can be made by examining the amountof dental plaque present on the animal's teeth before and after thecleaning. It can be made by examining the amount of tartar present onthe animal's teeth before and after the cleaning. It can instead be madeby examining the presence, intensity, or extent of gingivitis occurringin the animal before and after cleaning (or following a period of suchcleanings, such as over the course of a week or a month). Of course,these criteria can be combined to form a desired standard. Thus, forexample, a claim that the chew described herein cleans teeth aseffectively as weekly brushing when a chew is administered to an animalevery other day can reference a plaque-based standard, meaning that thedegree of plaque removal/prevention achieved by chew administration isroughly equivalent to the degree of plaque removal/prevention achievedby brushing.

When present in the chewable matrix, the abrasive may be substantiallyuniformly dispersed therein, dispersed in discrete regions thereof,coated on the surface of the matrix, or a combination of these. Theabrasive may, for example, be thoroughly mixed with the other dryingredients of the chewable matrix prior to their combination with wetingredients, resulting in a chewable matrix having the abrasive disposedsubstantially uniformly throughout. Alternatively, a wet preparation ofthe abrasive may be crudely mixed with the remaining, hydratedingredients of the chewable matrix prior to melting and forming,resulting in a chewable matrix having ‘pockets’ of abrasive materialdisposed therein (the uniformity of the disposition depending on thedegree and aggressiveness of the mixing). In still another alternative,an abrasive may be mixed with an adhesive containing a volatile solventand the mixture may be sprayed on the exterior of a formed animal chew,resulting in a chew having a thin layer of abrasive adhered to theexterior surface thereof.

In addition to exerting an abrasive effect, an abrasive applied to thesurface of an animal chew can serve other purposes, such as lubricatingmanufacturing components and conferring a desirable texture to theexterior surface of the chew. By way of example, a bolus of meltedchewable matrix made as described herein, a mold used to shape it, orboth, can be dusted with a particulate mineral or with a powderedcellulose to reduce the degree of adhesion between the melt and the mold(by becoming interposed between the hot melt surface and the moldsurface and preventing direct contact therebetween). A chew formed inthis manner will have a surface texture determined in part by thetexture of the particulate or powder which forms part of its surface.Such a chew may have a rougher texture that is pleasing to the mouth ofthe target animal, to the hand of a human providing the chew to thetarget animal, or both.

Abrasives are preferably selected to have a hardness less than theactual or anticipated hardness of the teeth of the target animal. Suchabrasives can be expected to scour the surface of the teeth againstwhich they are scraped without damaging the tooth itself (e.g., withoutscratching tooth enamel).

Anti-Tartar Agents

Anti-tartar agents are another important class of dental prophylacticingredients that can be included with the animal chews described herein.As with abrasives, anti-tartar agents can be included on or in a chew atsubstantially any location and in any configuration in which contactbetween the anti-tartar agent and a tooth surface can be effected. Theycan, for example, be included at any surface or within any material thatis anticipated to contact an oral fluid during mastication of the chew.

Anti-tartar agents are preferably situated on, within, or both on thesurface of and within the chewable matrix of the animal chews describedherein. Such a configuration will tend to enhance contact between theagent and tooth surfaces of the animal, since it is upon the chewablematrix that the target animal can be expected to chew. Preferably, oneor more anti-tartar agents is disposed throughout the chewable matrix,so that tooth surfaces are contacted with the agent throughout theperiod during which the target animal masticates the chew.

The identity of the anti-tartar agent(s) included in the animal chew isnot critical. Numerous such agents are known in the art, as are theconcentrations at which their respective anti-tartar effects.Substantially any known anti-tartar agent(s) can be used in the animalchews, consistent with the other parameters set forth herein. By way ofexample, the amount and identity of the agent used should be consistentwith the desired properties (e.g., hardness, ductility, and resilienceof the chewable matrix) of the chew and the suitability of the agent foringestion by the target animal.

A suitable class of anti-tartar agents for use as a component of thechewable matrix in the animal chews described herein is metal chelatingagents. Many such agents are known and are used in human and veterinarydentifrices. Polyphosphates are common anti-tartar agents, theirefficacy and safety for this purpose having long since been established.Suitable polyphosphates include sodium tripolyphosphate, tetrasodiumpyrophosphate, sodium hexametaphosphate, and combinations of these. EDTA(ethylenediamine tetraacetic acid) and related compounds are also wellknown metal-ion chelating agents. Without being bound by any particulartheory of operation, metal chelating agents are believed to exert theiranti-tartar effects by binding metal ions that help to maintain thestructure of tartar on tooth surfaces. Particularly when used incombination with abrasives, anti-tartar agents can lead to tartarremoval by weakening the physical structure of tartar. Because theefficacy of metal chelating agents for anti-tartar purposes can beinhibited by the presence of free metal ions, animal chews which includea metal-chelating anti-tartar agent should be formulated to limit freemetal ions released from the animal chew upon its mastication.

Green tea extract and other plant extracts are known to havetartar-inhibiting and -removal functionality, and such extracts can beincorporated into the chews described herein.

Tooth-Strengthening Agents

Another class of dental prophylactic ingredients suitable for use in theanimal chews described herein is fluoride-containing compounds and othertooth-strengthening agents, such as sodium monofluorophosphate. Suchagents and their use for dental prophylactic purposes are well known inthe art, and substantially any of them may be included in the animalchews describe herein, so long as the identity(ies) and amount(s) ofsuch agents are consistent with the other parameters of the chews setforth herein (e.g., hardness, ductility, and resilience of the chewablematrix and suitability of the agents for ingestion by the targetanimal).

Surface-Acting Agents

Yet another class of dental prophylactic ingredients suitable for use inthe animal chews described herein is surface-acting agents, such assurfactants and tooth enamel-whitening agents. Such agents and their usefor dental prophylactic purposes are well known in the art, andsubstantially any of them may be included in the animal chews describeherein, so long as the identity(ies) and amount(s) of such agents areconsistent with the other parameters of the chews set forth herein(e.g., hardness, ductility, and resilience of the chewable matrix andsuitability of the agents for ingestion by the target animal).

Prophylactic Pharmaceutical Agents

Still another important class of dental prophylactic ingredientssuitable for use in the animal chews described herein is prophylacticpharmaceutical agents intended for topical delivery to teeth and gums.Examples of such pharmaceutical agents include antimicrobial agents,anti-inflammatory agents, and other agents effective to treat or preventgingivitis. Other examples include antibacterial or antiviral agentsintended for topical application to oral lesions. A wide variety of suchagents and their use for dental therapeutic and prophylactic purposesare known in the art. Substantially any of them may be included in theanimal chews describe herein, so long as the identity(ies) and amount(s)of such agents are consistent with the other parameters of the chews setforth herein (e.g., hardness, ductility, and resilience of the chewablematrix and suitability of the agents for ingestion by the targetanimal). Veterinary pharmaceutical agents having therapeutic effect areincluded within the class of dental “prophylactic” ingredients inrecognition of the fact that treatment of oral disease symptoms andconditions will often prevent further problems, as well as for the sakeof convenience. Terminology notwithstanding, veterinary pharmaceuticalingredients intended for oral topical delivery for solely therapeuticpurposes are included within the class of dental prophylacticingredients for the purposes of this disclosure.

This disclosure does not purport to list all agents having oral activitythat could be effectively delivered to the oral cavity of a targetanimal by way of the animal chews described herein. A skilled artisancan identify agents beyond those explicitly identified herein that canbe effectively delivered using the animal chews.

Breath Agents

Instead of, or in addition to dental prophylactic ingredients, theanimal chew described herein can be used to administer a breath agent toa target animal. Animals such as dogs frequently exhibit odiferousbreath, attributable to a variety of causes, including poor dentalhygiene, ingestion (and/or regurgitation) of foul-smelling compositions,and colonization by microorganisms that produce undesirable odors. Thetooth-cleaning ingredients and actions of the animal chews describedherein can mitigate odors attributable to dental hygiene issues, but maynot mitigate other causes. Inclusion of one or more breath agents canaddress those causes.

Breath agents can be any of at least three types: perfumes, deodorants,and antimicrobial agents. Perfumes are scent-masking agents that obscurethe presence of a disagreeable odor. Selection of a suitable perfumeshould take into account the odor sensitivity of the individual fromwhom the odor is to be obscured (e.g., typically a dog's care-giver,rather than a dog). Deodorants are compounds which capture or degradecompounds which are detectable as odors. Antimicrobial agents, bycontrast, kill, inactivate, or modify the activities of microorganismsthat generate odor-causing compounds. Each of these types of breathagent and their use for improving breath scent is known in the art.

Examples of suitable breath agents include plants (e.g., shredded mintor oregano leaves), plant extracts (e.g., mint or citrus oils, herbssuch as spearmint, parsley, or parsley oil, chlorophyll, or a green teaextract), bicarbonate salts (e.g., baking soda), disinfectants (e.g.,menthol), and combinations of these. Other agents known to improve ormitigate undesirable breath odors can also be used.

As with other components of the animal chew, breath agents should beselected and used in amounts consistent with the other parameters of thechews set forth herein (e.g., hardness, ductility, and resilience of thechewable matrix and suitability of the agents for ingestion by thetarget animal). Because breath agents tend to be used in relativelysmall amounts, these considerations are often minor, and are in anyevent within the ken of a skilled artisan in this field.

Pharmaceutical Agents

Instead of, or in addition to dental prophylactic ingredients and breathagents, the animal chew described herein can be used to administer aveterinary pharmaceutical agent to a target animal. Inclusion oftopically-applied pharmaceutical agents on or in the animal chew isdiscussed elsewhere in this disclosure. However, the pharmaceuticalagents that can be effectively administered to the target animal are notlimited to those intended for topical oral activity. Consumable portionsof the animal chew and oral fluids which contact any portion of theanimal chew are swallowed by the target animal. As a result, anyveterinary pharmaceutical agent that is present in these materials isdelivered to the GI tract of the target animal.

Veterinary pharmaceutical agents that can be administered using theanimal chew described herein include those intended for topicaladministration to a GI tract locus proximal to the stomach (e.g., theesophagus). Such agents also include pharmaceutical agents intended forsystemic administration by way of absorption through mucosa of the GItract, such as in the stomach, the intestines, or the bowel of thetarget animal.

Administration of a veterinary pharmaceutical agent using the animalchew described herein can be particularly beneficial when an extendedperiod of agent administration is desired. If the agent is dispersedthroughout a resilient portion of the animal chew (e.g., the chewablematrix), the agent will be delivered to the target animal's GI tractonly as that resilient portion is ingested. Because the resilience ofthe animal chew (especially including its chewable matrix) is selectableas described herein, the rate at which a pharmaceutical agent carried inthe resilient portion of the chew will be administered to a targetanimal is likewise selectable. The animal chew described herein can thusbe used as an extended-delivery drug delivery device for dogs and otheranimals having a tendency to chew.

The identity of veterinary pharmaceutical agent(s) included in theanimal chew is not critical. Agents that are soluble in one or morecomponents of the chewable matrix and which can withstand themelt-processing techniques described herein are preferred, because theycan be incorporated into the chewable matrix to yield a chew thatdelivers the agent over an extended period at a rate limited by the rateat which the chewable matrix is consumed by the target animal.Veterinary pharmaceutical agents can also be applied to the surface ofthe animal chew in substantially the same ways such agents can beapplied to the surface of other objects (e.g., rawhide animal chews).

Taste-Masking Agents

The animal chew described herein is intended to be a highly palatablearticle that a target animal will desire to masticate. The presence onor in the chew (e.g., as a component of the chewable matrix thereof) ofone or more compounds having an undesirable flavor or odor can diminishthe palatability of the article. If such a compound is a desiredcomponent of the chew, a taste-masking ingredient can be included in anamount sufficient to render the chewable matrix palatable to the animal.Numerous taste-masking compounds and techniques are known in the art,and substantially any of those can be used, so long as they areconsistent with the other parameters of the animal chew describedherein. By way of example, a taste-masking compound that is highlyappetizing to the target animal can overwhelm an undesirable tasteimparted by another component of the animal chew. Likewise,encapsulation of the compound having an undesirable taste (e.g., aveterinary pharmaceutical agent intended for systemic delivery) in amaterial such as polymeric microspheres that does not substantiallyrelease the bad-tasting compound in the oral cavity, but does release itin a higher-pH environment such as the stomach, can be employed to maskan undesirable taste of a component.

Chew Time

An important characteristic of the animal chews described herein is thecumulative period of time that a target animal must masticate upon thechewable matrix of the chew in order to completely consume it.

The chew time of an animal chew depends on several factors, including atleast the characteristics of the target animal, the composition of thechewable matrix, the size and shape of the chewable matrix, and thegeometry of the animal chew (to the extent that the geometry mayrestrict access of the target animal to the chewable matrix). Otherfactors (e.g., temperature and humidity) may also affect the chew timeof the chew, but these factors will tend to be relatively minor underconditions of normal use of the chews, and can be assumed to beapproximately equal to ambient indoor conditions in atemperature-controlled residential room at 20 degrees Celsius and 75percent relative humidity at sea level for the purposes of thisdisclosure.

Although the characteristics of individual animals will be expected tovary among any group of target animals, artisans in the field of animalchew products routinely identify rough classes of animals. The animalchews described herein can be designed to exhibit an approximatecharacteristic chew time for rough classes of target animals. Although‘chewing tenacity and strength’ (“chew tenacity”) is not a commoncriterion for classification of animals, other physical characteristics,such as body weight or height, can be used as an approximate correlateof this criterion. Other characteristics, such as state of health orvigor, age, and satiety can affect the chewing behavior of an individualtarget animal at any given point in time. Despite these individualdifferences, artisans in this field nonetheless are able to roughlyclassify animals into arbitrary groupings for the purpose of identifyinganimals having roughly similar chewing properties. The characteristic(s)used to classify target animals are not critical, but should generallybe selected to roughly correlate with chew tenacity.

By way of example, dogs are a highly diverse species of animal withnumerous recognized breeds of varying sizes and physiques. Nonetheless,dog breeds and individual dogs are commonly classified as “small” (notmore than 15 pounds ordinary body weight), “medium” (more than 15, butnot more than 35 pounds ordinary body weight), and “large” (more than 35pounds ordinary body weight) dogs. Alternatively, dogs (and horses) canbe characterized by their height-at-withers (withers being the ridgebetween the animal's shoulder blades), with “small” dogs beingcharacterized as those having a height at withers of not more than 15inches, “medium” dogs being those having a height at withers of morethan 15 inches, but not more than 25 inches, and “large” dogs beingthose having a height at withers of more than 25 inches. Large dogs willgenerally consume an animal chew more quickly than a medium dog willconsume the same chew, and the medium dog will generally consume theanimal chew more quickly than a small dog. Put another way, the chewtenacity of large dogs is greater than that of medium dogs and greaterstill than that of small dogs.

For illustrative purposes in this disclosure, dogs will be classified assmall, medium, or large based on the foregoing ordinary body weightcriteria, with ordinary body weight being the average weight of ahealthy dog over the course of a week.

Compositions for the chewable matrix of the animal chew described hereinas well as the geometrical shape of the chew is described elsewhere inthis disclosure. If these two factors which affect chew time are heldconstant, the two remaining primary variables that can affect chew timeare size of the chew and characteristics of the animal. If size of thechew is also held constant, it is apparent that a large dog will consumethe chew more quickly than a medium dog, which will, in turn, consume itmore quickly than a small dog. If animal chews of a given shape andcomposition and having roughly equal chew time for the three types ofdogs are desired, then the size of the chew must be varied for the threeclasses of dogs. Thus, an animal chew having a chew time of about 5-10minutes for a large dog will be larger than an equivalently-shaped and-formulated animal chew having the same chew time for a medium dog, andboth of these will be larger than an equivalently-shaped and -formulatedanimal chew having the same chew time for a small dog. This explanationdemonstrates that for a given animal chew formulation and shape, thesize of the chew should vary in proportion to a classification of ananimal chew tenacity if the chew time of the animal chew is to beapproximately equal across the classification.

For dogs, animal chews having a variety of chew times can be made, thechew time depending on the purpose for which the animal chew will beused. For animal chews provided for the purpose of rewarding dogbehavior or relieving teething or chewing urge, a chew time of 1-30minutes can be desirable, with a chew time of about 1-2 minutes or about2-5 minutes for all classes of dogs being suitable examples. For animalchews provided for the purpose of cleaning dog teeth, a chew time of10-30 minutes can be desirable. For animal chews provided for thepurpose of delivering an active agent over an extended period, the chewtime should be approximately equal to that extended period. If the sameanimal chew formulation is to be used for each of these purposes for alldog classes, then the corresponding animal chew can vary in size. If thesame size animal chew is to be used for each of these purposes for alldog classes, then the composition of animal chew can be varied.

The chew time of animal chews intended for dogs should preferably notexceed the attention span of a target dog. By way of example, the animalchew should be completely consumable by the dog within several minutes,such as within about 5, 2, or one minute.

Shape of the Animal Chew

A significant feature of at least one embodiment of the animal chewdescribed herein is its geometric shape, which is selected to enhancethe dental cleaning efficacy of the chew. In particular, there areseveral features of the geometric shape which enhance its dentalcleaning efficacy. First, it includes numerous nubs and ridges,preferably over most or substantially all of the surface of the chew.Second, it can have a generally curved shape to prevent it from lyingflat on a flat surface (and thereby enhancing the ability of a targetanimal to pick up the chew from a flat surface for chewing). Third, thechew can have a twisted shape that tends to orient nubs, ridges, edges,or other parts of the chew in a manner that enhances tooth-to-chewcontact (the chew can, of course, have both a generally curved shape anda twisted shape, such as the chew illustrated in FIG. 1). Fourth, thechew has a shape that facilitates its production from a molten mass,such as in a rotary or plate mold. The shape of the chew is alsorelatively compact and lacks sharp edges, both of which reduce thelikelihood of damage to the chew during packaging, storage,transportation, storage, and retail sale. Optionally, the chew can havea cavity or hollow which can be empty or which another material canoccupy. The chew can also have an overall shape that is pleasing to thetarget animal or a care-giver of the target animal.

The shape of the chew includes multiple nubs and ridges on its surface.When chewed by a target animal, these nubs and ridges tend to contactthe teeth and gums of the target animal at surfaces proximal to the tipsof the teeth. Compared with chewing a flat slab of material, chewing ofthe relatively rough or ridged surface of the chew tends to result in afuller extent of contact between all areas of the target animal's teeth.The nubs and ridges are preferably disposed and spaced in configurationsthat accommodate teeth of the target animal between the nubs and ridges,so that biting upon the chew will tend to urge the apices of the nubsand the crests of the ridges toward the roots the animal's teeth andtoward its gums as the teeth slide into the spaces between the nubs andridges. Thus, for target animals having small, relatively closely-spacedteeth, animal chews having relatively closely-spaced nubs and ridgeswill tend to scour the target animal's teeth more thoroughly than anequivalent chew having more broadly-spaced nubs and ridges. Conversely,an animal chew having relatively broadly-spaced nubs and ridges caneffectively scour (i.e., contact and abrade) a greater proportion of thetooth surfaces of a target animal having similarly broadly-spaced teeth.

The heights of nubs and ridges on the animal chew are preferablycomparable to (i.e., on the order of the same size as, or 10%, 25%, or50% of) the length that at least some teeth of the target animal extendbeyond the gum. Nubs and ridges having these heights are able to abradeteeth near their tips and along a substantial portion of the perimeterfaces of these teeth, toward the gum line.

In one embodiment, the animal chew has nubs, ridges, or both,substantially covering the surface of the chew, including at least partof two opposed, substantially parallel faces thereof and part of theintervening transitional surface that extends between the two opposedfaces. The nubs and ridges can cover substantially the entirety of eachsurface of the chew (e.g., as shown in FIG. 1). By way of example,substantially the entirety of each of the two opposed faces can becovered with nubs, and substantially the entire intervening transitionalsurface 40 can be covered with ridges that extend between the twoopposed faces (e.g., as shown in FIG. 6). Such a chew can be relativelyeasily extricated from a mold formed by two plates that meet at partingline 42, the mold plates each having a cavity corresponding to the shapeof half of the chew, since the ridges will tend to slide out of the moldplate cavities as the chew is removed therefrom. By contrast, if thechew had one or more nubs extending outwardly from its transitionalsurface 40, such nubs could interlock with the corresponding portion ofthe mold cavity and prevent or inhibit release of the chew from thecavity.

The nubs 12 can have a variety of shapes, but tend to extend generallyaway from the surface of the chew from which they arise, generally in adirection perpendicular to that surface. Nubs can have substantially anythree-dimensional geometric shape, such as conical, frusto-conical,rounded, or domed. The nubs can be relatively sharp (i.e., have an acuteapex, rounded or not) as shown in FIG. 12, more rounded and blunt asshow in FIG. 5, be approximately hemispherical as shown in FIG. 23H, oreven be more nearly globular as shown in FIG. 26E (in which instance thenubs may be indistinguishable from bulges 16 on the chew). The number ofnubs disposed on a surface of the pet treats is not critical, nor istheir patter or layout. Nubs 12 on a surface can be of substantiallyuniform size as shown in FIG. 25A, of alternating sizes as shown in FIG.25B, or of a variety of sizes.

The shape(s) of ridges 14 present on one or more surfaces of the animalchew are similarly not critical, and an animal chew may include two ormore ridges of varying shape, size, direction, and height. By way ofexample, ridges 14 can extend straight across a surface, such as theridges 14 having a rounded profile that extend completely across thetransitional surface 40 of the chew depicted in FIG. 3. Ridge crests mayalso be curved as shown in FIG. 24C or rippled, as shown in FIG. 25C.

As the animal chew is masticated and consumed by the target animal, thechew will tend to crumble and its surface will frequently develop a moreirregular shape than its initial shape. This can be beneficial, in thatthe increasingly-irregular shape can be better able to contactrelatively remote tooth surfaces within the mouth of the target animaland improve the dental cleaning efficacy of the chew. Furthermore,degradation of the chew upon mastication can also cause its shape tomore nearly approximate the contours of the dentition of the individualtarget animal, further improving its dental cleaning efficacy.

The animal chew can have a generally curved shape as shown in FIGS. 5and 23H, an axially twisted shape as shown in FIGS. 7, 17, and 27H(i.e., a chew having ends that are rotationally offset from one anotherabout the axis of the shaft, with a degree of axial twist equal to anglealpha is shown in FIG. 17), both as shown in FIG. 3, or neither as shownin FIG. 6. An animal chew having a generally curved shape will not lieagainst a flat surface with either of its opposed surfaces flush againstthe flat surface. This feature facilitates grasping of the animal chewby a target animal when the chew rests upon a flat surface. An animalchew having an axially twisted shape will also not lie against a flatsurface with either of its opposed surfaces flush against the flatsurface and likewise facilitates grasping of the animal chew by a targetanimal when the chew rests upon a flat surface.

The curved and twisted shapes of the animal chew can result inorientation of nubs and ridges (and corresponding surfaces of the chewfrom which they extend) at a variety of angles relative to an end 80 ofthe chew, so that when a target animal grasps the chew at its end (e.g.,a dog holding an end between its front paws while gnawing on theopposite end of the chew) nubs and ridges will extend from the oppositeend of the chew at a variety of angles and will engage the targetanimal's teeth at a variety of angles when the animal masticates thechew. The orientation of the chew ends and the nubs and ridges, as wellas the animal's efforts to gnaw the chew from various angles, will causea greater proportion of the surface area of the animal's teeth to bescoured by the chew than if the chew were straight and had nubs andridges extending therefrom in a more limited number of directions. Thus,the overall-curved and axially-twisted shape of the chew can enhance thedental cleaning efficacy of the chew.

An important aspect of the shape of the animal chew described herein isthat the shape can facilitates production of the chew by various methodsdescribed herein.

For embodiments in which the chew has two opposed faces substantiallyparallel to one another (whether or not the opposed faces are planar orcurved) and ridges having a substantially uniform profile along theirlength extend between the two opposed faces about the transitional faceof the chew (see, e.g., FIGS. 1-5), the chew can be formed by cutting aslab of chewable matrix in the direction perpendicular to the opposedfaces (e.g., using a die having the shape of the perimeter of theopposed faces). The uniformity of the transitional face between theopposed faces in the direction perpendicular to those faces facilitatesnumerous methods of forming the chew. By way of example, the slab can becut prior to or as a part of the same molding operation that imparts atexture (e.g., a nub-covered surface) to one or both of the opposedfaces.

For embodiments in which the chew is symmetrical about a plane ofsymmetry that is twisted by an angle alpha (see FIG. 17, alpha beingbetween −90 and +90 degrees, preferably being between −45 and 45degrees) along the long axis of the chew (see, e.g., FIGS. 6-16), thechew can be formed between two mold plates, each plate having a cavitythat accommodates a portion of the chew including one of the two opposedfaces. So long as the transitional face 40 does not include a portionthat extends outwardly therefrom at a position distal (within the moldcavity) to the parting line 42 formed at the interface of the two moldplates, the molded chew can be lifted from the mold cavity withouttwisting the chew. That is, because the transitional face of the chew(i.e., the face that contacts the lateral sides of the mold cavities issmooth (even if it is ridged, scalloped, or fluted; see FIG. 31), thechew can be lifted from the cavity perpendicularly to its depth and themargins of the chew so lifted will not impinge upon the lateral sides ofthe mold cavity. The ease with which the molded chew can be removed fromthe mold cavity when it has this shape facilitates its manufacture by avariety of molding processes, as described herein.

Similarly, nubs and ridges extending from the opposed faces of the cheware oriented at angles such that the nubs and ridges formed upon moldingthe chew do not impinge upon the surface of the mold cavity when themolded chew is lifted from the cavity perpendicularly to its depth.

Fabrication of the animal chews and improved resistance to chipping canbe conferred by including a chamfer 44 at edges where surfaces wouldotherwise meet at a sharp (e.g., >45 degree) angle. By way of example,the animal chew depicted in FIG. 32 has a shape that includes a chamferextending about the perimeter of the visible opposed face (which bearsnubs) where it meets the fluted transitional face of the chew.

The animal chew can have a shape that defines a cavity 50 or hollow thatis bounded by the body 10 of the chew. The cavity can be left empty(i.e., a void within the body) as shown in FIGS. 23H, 26F, 27D, and27E-27H. Alternatively, the cavity can have a filling 55 therein,filling a portion or all of the cavity as shown in FIGS. 1-5 and 27A.

The overall shape of the animal chew is not critical, and preferably isa shape that is pleasing to the target animal or to a care-giver of thetarget animal. The overall shape need not have any particular relationto the efficacy of the animal chew for any purpose, and can instead beornamental, whimsical, or selected to evoke another object. By way ofexample, for animal chews intended for dogs, the chew can have anoverall perimeter shape evocative of a generic “bone” (see FIG. 18), itbeing commonly known that dogs generally favor chewing upon bones. Otheroverall shapes can be selected, such as rings and loops (FIGS. 23H 26F),rods and sticks (FIGS. 29B, 29C, and 30), toothbrush-like shapes (FIGS.26G, 28B, and 28F), analogs of cut bones or meats (FIGS. 28A-28E), disks(FIG. 29A), abstract shapes (FIG. 26E), and combinations of these (FIGS.26A, 26B, 26F, 26H, 27F-27H, FIGS. 28A-28F, and FIG. 30).

An animal chew having the overall perimeter shape of a generic “bone”(see, e.g., FIG. 1C) includes an elongate shaft 70 with two ends 80,each end including one or more condyles 82 (or, more properly one ormore shaped parts resembling the condyle of a bone such as a bovinefemur). Such a bone-shaped animal chew can be twisted about its longaxis, as shown for example in FIG. 7, although it need not be so twisted(compare, e.g., FIGS. 6 and 7). A bone-shaped animal chew can also havea general curved shape, as shown in FIG. 5, wherein the long axis of thechew is curved in the direction of one (a “C”-shaped curved shape) orboth (an “S”-shaped curved shape) of the opposed surfaces of the chew,regardless of whether the chew is also twisted about its long axis. Thechew illustrated in FIG. 5, for example, exhibits a C-shaped curvedshape and is not twisted about its long axis and has bi-lobedcondyle-like shapes at both of its ends.

The opposed faces 20 and 30 of the animal chew are preferablyapproximately parallel to on another across the surfaces of both faces,but they need not be. As shown for example in FIGS. 26C, 26F, 27G, 27H,and 28A-28F, some or all of the opposed faces may be rounded and notparallel to one another, or even a opposed portions of a single roundedface (see, e.g., FIGS. 26E and 26F).

Many animal chews of the type described herein will have opposed firstand second surfaces 20 and 30, the opposed surfaces being relativelylarge relative to the breadth of the transitional face 40 that extendsbetween the opposed surfaces. However, this need not be so. FIG. 30depicts several embodiments of the animal chew in which the breadth ofthe transitional face 40 significantly exceeds the size of the twoopposed faces 20 and 30. Comparing FIGS. 1 and 30F, it can be seen thatthe filling 55, when present can be of relatively small size relative tothe sizes of the opposed faces (as in FIG. 1), and can be substantiallyequal in thickness to the breadth of the transitional face 40. However,the size of the filling can substantially exceed the size of both theopposed faces 20 and 30 and the thickness of the transitional face 40,as shown in FIG. 30F.

The shape of the animal chew can affect its consumption by animals,including its frangibility and digestibility. Because the chews arenormally intended to be consumed by the animal permitted to gnaw uponthem, it is important that pieces of the chews generated during chewingbe digestible and non-injurious to the animal. It is not always possibleto predict the size of the pieces to which an animal will reduce thechew prior to swallowing the pieces. Some animals (e.g., large dogs)will tend to swallow relatively large pieces, especially when the animalis very hungry. Thus, the shape of the chews described herein should beselected to encourage production of digestible pieces upon normalchewing and to account for the possibility of swallowing large pieces(or even the entire chew, whole).

Once swallowed, the chewable matrix can be digested within the digestivetract of the animal which swallowed it. Digestion involves absorption bythe matrix of liquid present in the digestive tract, combined withchemical and enzymatic action exerted upon the matrix by components ofdigestive tract liquid and mechanical action exerted upon digestivetract contents by muscles lining the tract. These actions combine tocause the chewable matrix to break up, dissolve, disperse, and besuspended in fluids in the digestive tract and to thereafter be eitherabsorbed by the animal or included within wastes subsequently excretedfrom the digestive tract. As with other swallowed materials,digestibility of the chewable matrix can be enhanced at least bydecreasing the size of matrix pieces that are swallowed and by enhancingthe contact of swallowed matrix pieces with digestive fluids. Both ofthese factors can be influenced by the shape of the animal chew.

The size of matrix particles swallowed by an animal gnawing upon thechew described herein is strongly influenced by the frangibility of thechewable matrix and the degree to which the animal chews the matrix(i.e., number of chews and the force applied). In order for a piece ofthe matrix to be broken away from the animal chew, the forces applied tothe chew must exceed the cohesive strength of the matrix along a breaksurface at which the piece breaks away from the bulk matrix. Roughlyspeaking, the magnitude of the force required to break a piece away fromthe bulk matrix will increase as the size of the break increases. Thus,the geometry of the bulk matrix can influence the amount of force whichmust be applied to it in order to break off pieces. Relatively narrowportions of bulk matrix, for example, will tend to require less appliedforce to fracture than broader portions. By way of example, a sphere ofuniform matrix material will require the same force to fracture intohalves regardless of the direction in which chewing force is applied tothe sphere. By contrast, an elongate cylinder will tend to fractureacross its circular cross section with less applied force than isnecessary to fracture it along its long axis (because thecross-sectional break surface is smaller than the longitudinal breaksurface). Similarly, relatively thin portions (e.g., sheet-, rod-, orcone-like structures) will tend to fracture with less applied force thanrelatively thick portions. This characteristic of the matrix materialcan be beneficially used to enhance the likelihood that the animal chewdescribed herein will be chewed into relatively small, digestible piecesbefore the pieces are swallowed by the animal to which the chew isprovided.

Frangibility of the chew can also be influenced by its shape by focusingapplied forces at certain points of the chew. It is well known in thefield of material science that the geometry of an object to whichexternal forces are applied can tend to focus those applied forces atcertain points or planes (i.e., “break points”) in the object. By way ofexample, when external tensional force is axially applied to an elongatecylindrical rod of a uniform material, the rod having a portion with across-sectional diameter that is smaller than the rest of the rod, it iswell known that the rod will tend to break at the narrowed portion(because the applied tension is greatest at that portion, considered ona force-per-unit-cross-sectional-area basis). Similarly, the shape ofarticles subjected to compressive or obliquely-applied forces canstrongly influence the deformation and breaking behavior of thearticles.

In order to promote degradation of the chew into relatively small,digestible pieces, the shape of the chew can be selected to yieldportions (“break points”) of the chew that are more easily broken thanothers. Thus, the shape of the chew can be selected so that it will tendto degrade, when chewed, into piece of predictable size. The size ofthose pieces can be selected to render them digestible by the normaldigestive processes of the animal to which the chew will be provided.

Digestion of the chewable matrix is dependent upon contact betweenfluids in the digestive tract of the animal gnawing upon it and thesurfaces of matrix pieces that are swallowed. Digestive action occurs,for the most part, at the liquid-matrix surface and at portions of thematrix into which the liquid is absorbed. Digestion generally involvesdegradative action of digestive liquids acting at or near the surface ofmatrix particles. As surface degradation progresses, the material at thesurface dissolves or dissociates away from the surface, revealingadditional matrix at the surface of which further degradation can occur.Thus, generally speaking, digestion of matrix particles is atemporally-dependent phenomenon in which larger matrix particles willtend to take longer to digest than smaller particles. However, becauseit is a surface phenomenon, digestion will occur at a higher rate as thesurface area of the matrix-to-digestive-liquid interface increases.Thus, even ignoring the effects of chewing and mechanical aspects ofdigestive processes, the rate of matrix digestion by an animal can beincreased by increasing the surface area of the particles that areswallowed by the animal. In terms of complete digestion of ingestedmatrix pieces, the rate of digestion of such pieces (or even of chewsswallowed whole) can be increased by increasing the ratio of the surfacearea of swallowed pieces to the volume of those pieces.

The digestibility of the chews described herein can be increased byselecting a chew shape that will tend to increase the ratio of thesurface-area-to-volume (the “SA-V ratio”) of pieces that are broken fromthe chew by the animal upon chewing and swallowed. By way of example, achew having a ‘feathery’ or highly-studded shape will tend to yieldrelatively small-volume pieces with relatively large surface area and,consequently a high SA-V ratio. Such pieces will exhibit more rapiddigestibility (and more complete digestibility over a short period oftime, such as 1-4 hours) than pieces having a smaller SA-V ratio.Methods of increasing the SA-V of pieces (e.g., by selecting orinfluencing their shapes to generally avoid compact shapes and togenerally favor elongate shapes or shapes having complex or invaginatedsurface configurations) are well known in the art. By way of example,the SA-V ratio of a chew can be increased by including ridges (concaveor convex), nubs, indentations, holes (i.e., extending completelythrough a portion of the chew), furrows or other complex surfacefeatures.

Even in the “worst case” (for digestibility) scenario in which an animalswallows whole a chew provided to it, a chew having a sufficiently highoverall SA-V ratio (i.e., the ratio of the outer surface area of thewhole, intact chew divided by the volume of its matrix) can be digestedby the animal. The precise SA-V ratio required to facilitate digestionif a chew is swallowed whole is a function of the composition of thechewable matrix, the identity of the animal by which it is swallowed,and other predictable factors which can be determined empiricallywithout significant experimentation. A skilled artisan is thereby ableto select chew shapes (i.e., each with an inherent SA-V ratio) that isappropriate to permit digestion of a swallowed-whole chew having aselected matrix by a selected animal. By way of example, chews intendedfor use by dogs and having one of the compositions described herein inExample 2 will preferably have an SA-V ratio greater than about 8,preferably greater than about 10, and even more preferably greater thanabout 12.

The animal chew shapes illustrated and described herein are merelyillustrative. Animal chews made from the materials described herein,using the processes described herein, having the properties describedherein, or a combination of these, can be made in substantially anyshape consistent with the parameters set forth herein.

Appearance of the Animal Chew

Apart from their shape, animal chews described herein can have a widevariety of distinct visual appearances. The chews can, for example bemade in a variety of colors by adding colorants to the chewable matrixthereof, as shown for example in FIG. 23.

The chew shown in FIG. 23A includes three portions a first portion 22, asecond portion 32, and an intermediate portion 52. In this figure, firstand second portions 22 and 32 have the same light brown color(regardless of whether they are made from the same chewable matrixmaterial). The intermediate portion 52 has a contrasting blue-greencolor. Apart from the colorants contained therein, each of the first,second, and intermediate portions 22, 32, and 52 can have the samechewable matrix formulation, or they each can have a distinctformulation.

Similarly in FIG. 23B, the chew portrayed consists of a chewable matrixhaving first and second portions 22 and 32 that are distinguishable bytheir color. Apart from the colorants contained therein, the first andsecond portions 22 and 32 can have the same or different formulations.

It can be beneficial to use color as an indicator of the type or contentof a chewable matrix or another portion of the animal chew. Especiallywhen multiple animal chews are made having similar sizes and shapes, butdifferent formulations, such color coding can aid a target animal'scare-giver (or the target animal itself, to the extent the colors can bedistinguished by the animal) to differentiate between the differentanimal chew formulations. Furthermore, the colors selected for chewablematrices having specialized formulations can be evocative of the activeagent contained therein. By way of example, chewable matrices containingmint or another breath agent can be colored blue or green, to evokeassociation with the green of mint plants or the blue color frequentlyassociated with breath-freshening products intended for use in humanoral care. White coloration, as shown in FIGS. 23F and 23J can evokeassociation with tooth-cleaning products, such as human toothpastes andother dentifrices. Red coloration, as shown in FIG. 23G can evokeassociation with a rubbery material that is not intended for consumption(and, indeed, FIG. 23G is an image of an animal chew of the typedescribed herein that includes no chewable matrix, but is insteadconstructed of a non-digestible rubbery polymeric material that issubstantially resistant to destruction by ordinary chewing action by adog). Brown coloration (i.e., the color of many prior art consumable dogtreats) can evoke a grain- or meat-flavored material and can be used toindicate chewable matrices intended primarily for consumption by ananimal. Combinations (see, e.g., FIGS. 23B, 23C, and 23F) of coloredmatrices can indicate multiple functionalities of animal chews (e.g.,consumability and breath-freshening action for the chew depicted in FIG.23B, breath-freshening and tooth-cleaning actions for the chew depictedin FIG. 23C, and consumability and breath-freshening and tooth-cleaningactions for the chew depicted in FIG. 23F). Coloration of the animalchew or portions thereof (e.g., a whitish exterior portion surrounding areddish central portion so as to resemble a cut of meat or a naturalbone) can be selected to appeal to an animal, to the owner of an animal(i.e., one who purchases the chew for another animal), or both.

Chewable matrices are not the only animal chew components that can becolored to indicate or evoke their functionality. Other portions ofchews can be color coded, such as non-consumable portions (red in FIG.23G), and functional inclusions incorporated as visible particles. Forexample, visible white particles which indicate or evoke tooth-cleaningfunctionality can be seen in the consumable brown chew depicted in FIG.23D. Similarly, breath-freshening functionality is indicated or evokedby the visible blue inclusions 18 that are visible in the white-colored(evocative of breath-freshening and tooth-cleaning activity) chewdepicted in FIG. 23J. Likewise, blue and white coloration (evocative oftooth-cleaning functionalities) are visible in the filling 55 that canbe seen within the cavity in the cut-open animal chew depicted in FIG.23E.

In addition to surface shapes such as the nubs, ridges, scalloped orfluted edges, and the overall shapes described herein, the animal chewcan have other shapes, such as for ornamental or functional purposes.Many animal chews formed between two matching mold plates as describedherein will exhibit a parting line 42, as highlighted in FIG. 7 and asis visible in each figure that makes up FIG. 23 (except FIG. 23H, inwhich the parting line is difficult to distinguish). The animal chewscan include prominent text or other indicia imprinted into, or disposedupon the chew (such as on or in the chewable matrix thereof). By way ofexample, text 19 depicting the registered trademark MILK-BONE is visibleimprinted into the chews depicted in FIGS. 23E, 23G, 24A, and 24B.

The animal chews can include multiple chewable matrices that are linkedor connected to one another by a non-consumable portion, such as by arope or indigestible plastic rod or ring.

In one embodiment, a chew-resistant, non-consumable portion of theanimal chew includes an orifice or recess adapted to securely fit aroundan end of the chewable matrix so that the chewable matrix can be gnawedupon by the target animal and chewed back to the perimeter of thenon-consumable portion. So long as the portion of the chewable matrixcannot be extricated from the non-consumable portion by the targetanimal, the non-chewed portion of the chewable matrix (e.g., arelatively small fragment that remains after the bulk of the chewablematrix has been consumed by the target animal can remain unavailable tothe target animal for further consumption. By sequestering the lastnon-consumed fragment of the chewable matrix within the non-consumableportion, the target animal can be prevented from swallowing thefragment. The chewable matrix and the non-consumable portion may eachhave a complementary whimsical shape, such as a toothbrush-shapedchewable matrix having a ‘handle’ portion that fits snugly within a‘handle’ shaped recess in a non-consumable portion made from rubber orchew-resistant plastic and having the shape of a human hand, a dog paw,a representation of a dentist, or the like. The non-consumable portioncan also serve as a convenient grip by means of which the target animalcan hold the chewable matrix in a relatively fixed position whilegnawing upon it.

The chew can be partially or completely coated with an edible material.It can also be partially or completely embedded in a shaped piece ofsuch a material. By way of example, a chew described herein can have aflavored coating sprayed or adhered to most or all of its surface, sothat the flavored coating induces mastication of the chew by a targetanimal to release the coating, followed by more sustained chewing uponthe chew itself. Similarly by way of example, a chew described hereincan be embedded in an easily-eaten matrix, such as a material akin todog kibble, with the easily-eaten matrix having the shape of a beefsteakor a chicken leg and the chew having the appearance of a bone, some orall of which is revealed upon consumption of the easily-eaten matrix bythe animal.

Uses for the Animal Chew

A significant advantage of the animal chews described herein is the easewith which they can be used to achieve their ends, relative to thedifficulty of achieving those same ends by other methods.

Previous methods for cleaning the teeth in the animal typically involvebrushing or scraping the teeth of the animal with an oral careinstrument, such as a toothbrush, scaler, or curette. Suchtooth-cleaning methods are often poorly tolerated by animals and aretime-consuming and technically difficult to perform even upon acooperative animal.

When an animal chew as described herein contains a dental prophylacticingredient (e.g., an anti-tartar agent, an abrasive, or atooth-strengthening ingredient), prophylactic veterinary dental care canbe performed substantially more easily—as easily as selecting an animalchew having an appropriate dental care ingredient in an appropriateamount and providing the animal chew to the target animal. Owing to theappetizing characteristics of the animal chew, the target animal willvoluntarily gnaw upon the chew, thereby effecting the desired dentalcleaning. The process can be repeated substantially as often as desired.

Previous methods for administering a veterinary pharmaceuticalcomposition to an animal involve delivering the composition to theappropriate body location in a reliable, observable manner. By way ofexample, topically-delivered compositions are delivered directly to thetopical site at which pharmaceutical action is delivered and, ifnecessary, the animal is prevented from dislodging the medicamentthrough rubbing, licking, or irrigation of the treated site.Particularly when the desired delivery site is within the oral cavity ofan animal, preventing the animal from dislodging medication from theapplication site can be challenging and may require anesthesia of theanimal. Systemically-intended compositions delivered by an oral routeinvolve reliably inserting a dosage form into the GI tract of the animaland observing whether or not the animal regurgitates, sequesters (e.g.,in a mouth cheek), or otherwise avoids passage of the dosage form to theGI tract.

When an animal chew as described herein is used to administer aveterinary pharmaceutical composition to a target animal, thecomposition is incorporated into an appropriate part of the chew, andthe chew is simply given to the target animal. Owing to the appetizingcharacteristics of the animal chew, the target animal will voluntarilygnaw upon the chew, thereby effecting delivery of the active agent. Theprocess can be repeated substantially as often as desired, and thedosage administered can be controlled by selecting the amount of thecomposition incorporated into the animal chew.

Previous methods for delivering nutrients (e.g., calories, vitamins,minerals, or agents for promoting health and favorable appearance ofskin or coat) to an animal involve incorporating the nutrients into afood that the animal will voluntarily consume. Alternatively, thenutrients can be incorporated into a dosage form and administered like aveterinary pharmaceutical composition, with the attendant problemsdiscussed herein.

As with tooth-cleaning compositions and pharmaceutical agents, when ananimal chew as described herein is used to deliver nutrients to a targetanimal, the nutrients can simply be incorporated into the chew (togetherwith a taste-masking agent, if necessary), and the chew can be given tothe target animal.

The animal chews described herein can, of course, simply be fed totarget animals as treats or foodstuffs, just as previously knownfoodstuffs and treats can be. Provision of treats or foodstuffs to ananimal by its care-giver can enhance the emotional bond between the two.

Target animals for which animal chews described herein are believed tobe particularly appropriate include animals that tend to enjoy chewingon articles, such as dogs, horses, rodents, and ruminant animals. Theshape selected for the animal chew should be chosen based on thepreferences of the target animal for which it is intended. For example,dogs tend to enjoy chewing on bulky, relatively rigid articles having ashape that fills a substantial fraction of their oral cavity, which iswhy ‘bone-shaped’ animal chews are highlighted in this disclosure foruse with dogs. Horses, by contrast, tend to enjoy chewing long, thinarticles that exhibit rigidity and toughness similar to that of grassesand grains which they frequently select for chewing. Accordingly, animalchews made from materials like those described herein should havestraw-like shapes, such as shapes similar to blades of grass orthin-walled tubes. Ruminant animals likewise tend to favor blade- andstraw-like chewing substrates.

Manufacturing Processes

A significant feature of the animal chews describe herein is the easewith which they can be manufactured by a variety of processes. Althoughthe details of various manufacturing processes differ substantially,each of these processes essentially involves two steps: first forming amolten mass from the starch, protein, and water components of thechewable matrix of the chew (optionally together with other ingredientssuch as a saccharidic processing aid), and then shaping the molten massinto the animal chew described herein before the molten mass cools orhardens sufficiently to inhibit or prevent the shaping.

Formation of the molting mass involves two processes, namely combiningthe components of the mass and heating the mass sufficiently that atleast some fraction of the starch therein undergoes gelatinization. Theprecise methods and order used to perform these processes is notcritical. However, what is believed to be important is that a sufficientfraction of the starch undergoes gelatinization that gelatinized starchchains can bind together the components of the mass upon cooling. Whilenot being bound by any particular theory of operation, it is believedthat gelatinized starch chains are able to interact with proteins, withdenatured and denaturing protein chains, with water, and with othercomponents of the mass. Upon cooling of the mass, interactions betweenstarch chains and other mass components binds the starch and the othercomponents together and to one another, thereby producing a plasticmatrix.

It has been discovered that judicious selection of starches, protein,other mass/matrix components and their respective amounts yieldsmatrices that exhibit theological properties (e.g., rigidity,deformability, integrity, and toughness) such that the matrices areperceived by various animals as desirable for chewing upon.

Advantageously, the components of the chewable matrices described herein(i.e., starches, proteins, and water) are normal components of animaldiets. Thus, in addition to encouraging mastication by animals, thechewable matrices described herein tend to be harmless (or evennutritionally beneficial) to the animals which chew upon them.

Another significant advantage of the chewable matrices is that thematrices can be formed in the presence of a wide variety of compoundsbeyond those needed for matrix formation. Thus, these compounds can beincorporated into the matrix and released therefrom when it is chewed byanimals. Such components can be incorporated into the matrix before itis heated above the starch gelatinization temperature, while the matrixis still molten, or while the matrix is solidifying upon cooling (e.g.,for temperature-sensitive ingredients). Because starch gelatinizationtemperatures tend to be relatively moderate (generally below 100 degreesCelsius and sometimes as low as about 55 degrees Celsius, the moltenmass can be formed at temperatures and for periods of time that will notsignificantly degrade many compounds and compositions having beneficialactivities.

In one embodiment, all components that will be included in the chewablematrix are combined and thoroughly mixed. After the mixing issubstantially complete (i.e., when the mixture is substantiallyhomogenous), the mixture is heated to the processing temperature. Theprocessing temperature is preferably maintained below the boiling pointof the mixture (approximately 100 degrees Celsius for pure water, buttypically 110 degrees Celsius or higher for the mixtures describedherein). At the processing temperature, at least some of the starch(preferably at least about 50% on a weight basis, and more preferably atleast about 80%) undergoes gelatinization. The heated mixture isconsider molten or a “melt” at this point, and it exhibits sufficientplasticity that it can be shaped.

The melt is delivered to apparatus or processes which confer a shape tothe melt, and the melt is cooled sufficiently quickly that the meltretains the conferred shape. Optionally, additional shape features canbe conferred to the melt (e.g., twisting of a molded bolus of the melt)after its initial shaping and while it retains at least limitedplasticity. Upon cooling to ambient temperature (about 20 degreesCelsius), the melt is no longer substantially plastic and it will retainthe shape(s) conferred to it, at least unless it is again brought to asignificantly greater temperature. The shaped and cooled bolus of themelt thus becomes the animal chew described herein.

Mixing of components used to form the melt preferably occurs prior toheating the mixture to form the melt. However, one or more of thecomponents can be preheated, the mixture can be heated during mixing, ora combination of these can be performed. Furthermore, one or morecomponents (e.g., heat-sensitive components) can be added to the mixtureafter heating has begun, after heating of the melt is stopped, or evenas the melt is cooling (so long as the melt retains sufficientplasticity to permit mixing of the component therewith).

In one embodiment, most or all dry components (e.g., starches, fibers,particulates, dry vitamins, and colorants) are thoroughly mixed beforeliquid components are combined with them. Similarly, some or all liquidcomponents of the melt can be mixed prior to combining them with the dryingredients. Owing to the substantial viscosity of the mixture that isheated to form the melt, it can be beneficial to mix fluids andfree-flowing solids prior to forming the mixture that is subjected toheating.

The apparatus(es) used to mix and heat the mixture are not critical, andsubstantially any equipment capable of achieving such operations can beused. Equipment designed for performing mixing and heating operations onhighly viscous materials, such as plastics, can beneficially be used. Byway of example, the melt can be prepared by both mixing its componentsand heating the resulting mixture in any of a wide variety of extrudersthat are available. Owing to the importance of controlling thetemperature of the melt, an extruder that permits control of thematerials passing therethrough is especially suitable for forming themelt.

It is beneficial when using an extruder that venting of gases whichexhaust from the melt be possible, such as by modulating the atmosphericpressure (or the internal pressure of the extruder barrel) to which themelt is subjected. A variety of extruders having this functionality areknown, and substantially any of them that is otherwise compatible withthe methods described herein can be used for melt formation. If thetemperature of the melt exceeds its boiling point (or the boiling pointof a liquid present as a distinct phase within the melt), thenvaporization of the liquid can be expected to occur. Such vaporizationwill induce formation of bubbles or pores through the matrix, decreasingthe integrity and increasing the friability of articles formed from themelt. To the extent that these properties of the formed articles falloutside ranges considered desirable for the animal chews describedherein, such vaporization should be avoided, such as by venting of gasesprior to final melt formation, temperature control of the melt, or acombination of these.

Substantially any method of shaping the melt can be used to yield theanimal chews described herein. Several such methods are exemplified inthis disclosure. In addition to those specifically exemplified,substantially any known method of conferring a shape to a viscous moltenfluid that stiffens as it cools can be used, such as casting infrangible molds or in a compressed particulate bed or injection molding.

After the desired shape of an animal chew has been conferred upon abolus of melt, the melt should be cooled so that it will retain theshape. If desired, the bolus can also be dried to reduce the watercontent of the melt material to a desired value (e.g., to about 14 to 18wt % for most of the compositions described herein). Such cooling and/ordrying preferably is performed in a controlled environment, such as adrying oven in which the temperature and humidity of the oven interiorcan be controlled. When reduction of moisture content is desired, suchreduction is preferably performed at a relatively high temperature(e.g., at 165-185° F.) in order to hasten the process. The moisturecontent of cooled animal chews can be preserved by packaging the chewsin moisture-retaining packaging, such as any of a wide variety ofplastic films which retard moisture passage across the film. Inclusionof a humectant, such as one or more of those described herein, can alsoinhibit moisture loss from the finished animal chew. The proportions ofwater and humectant in the final product should be selected in amountssufficient to confer chewable plasticity to the cooled chewable matrix.

Three methods for making the animal chew are illustrated in FIGS. 20-22.

Each of the three methods involves forming a melt using one or moreextruders. A body extruder 100 mixes and melts the starch, protein, andwater ingredients of the chewable matrix, together with any othercomponents desired for inclusion in the chewable matrix. Substantiallyany extrusion apparatus capable of sufficient heating and mixing toproduce a substantially homogenous melt at a temperature in excess ofthe gelatinization temperature of at least most of the starch in themixture can be used, such as commercially available twin-screwcooker-extruder. Selection of an appropriate extruder is within the kenof an ordinary artisan in this field, in view of the desired processingcapacity of the apparatus and temperature of the extrudate.

If desired, a second extruder, herein designated a filling extruder 200for illustrative purpose, can be used to provide a second melt that canbe coextruded with the first melt obtained from the body extruder 100.The first and second melts can be used to generate animal chews having abody with a filling in a cavity or hollow thereof, to form a bodycomprising multiple chewable matrices (see, e.g., FIG. 23 B), or acombination of these. Additional extruders can also be used to provideyet more melts which can be combined with the first and second melts, ifdesired.

The melts from body and filler extruders 100 and 200 (if present) arecombined and processed further in the three processes illustrated inFIGS. 20-22.

FIG. 20 illustrates a compression molding process for making the chewsdescribed herein. Compression molding is commonly used for a variety ofrubbers and thermosetting plastics, but the process described hereindiffers substantially. Compression molding techniques used for rubberand plastic involve filling a mold with a resin or particulate matterand heating the mold under pressure to heat and set the resin orplastic. Compression molding techniques tend not to be used forconsumable foods or animal products for a variety of reasons, such asthe unsuitability of the components of most such products for suchprocessing, the substantial irreversibility of the process, andincompatibility of desired product shapes with such processing. Thecompression molding process illustrated in FIG. 20 is amenable tocontinuous and semi-continuous production of molded articles, such asthe animal chew described herein.

The animal chews described herein have a composition that is well-suitedto compression molding. The chews are made using materials that aremolten or resemble molten plastic materials. The chews are formed whiletheir material is in its molten or molten-like state. It is desirablethat the chews attain an irreversible shape upon molding. The chews haveshapes (e.g., complex surfaces, such as the closely-spaced raised nubsand an overall ‘twisted’ conformation) that are amenable to moldingunder pressure, and which are preferably formed by molding underpressure. Because the chews described herein can be made from a molten,plastic extrudate, it can be unnecessary to heat the molds in which theextrudate is compressed (unlike many known compression moldingprocesses). Thus, even though compression molding process are known in ageneral sense, their application to making pet chew products is believedto be uncommon or even unprecedented, especially for the formulationsdescribed herein.

FIG. 20 illustrates a process involving formation of individual billetsof melt, followed by shaping of the billets within a two-piece mold.Combined melt obtained from body and filler extruders 100 and 200 is fedto a portioning manifold 1100, which portions the melt into individualbillets, each of which is ultimately used to form a single animal chew.The billets are warmed sufficiently (generally at the time they exit theextruder) that they have a moldable, plastic texture suitable forforming in a compression mold. The billets are kept in a warm, plasticstate at least until they are molded. Extrudate retains substantial heatas it emerges from an extruder, and transport and manipulation ofextrudate (e.g., delivery to and processing by a portioning manifold)can often be achieved without substantial diminishment of itsmoldability. Of course, supplemental heating can be performed to ‘boost’the moldability of an extrudate portion if desired.

An individual billet is delivered between two mold forms, hereindesignated a bottom stamping former 1200 and a top stamping former 1300.The two mold forms define the three-dimensional shape of a desiredanimal chew (such as one of the chews described herein) when they arecompressed together. The plates are so compressed with the still-plasticbillet interposed between them within the matching molding cavities ofthe two plates. An example of one of the two mold forms is shown in FIG.20B, with a molded billet present in the molding cavity thereof; amatching mold form is visible in the background. Once formed, the billetis cooled to a temperature at which it retains its form. Thereafter, theformed billet is transferred to an oven dryer 900 to reduce its moisturecontent to a desired level, and thence to a tumbler 1000 in which theformed billet is tumbled with other formed billets or other materials toremove excess material or flashing resulting from overfill of themolding cavities beyond its capacity. Tumbled formed billets are furthercooled in a cooler 1400 to reduce their temperature before they aretransferred to a packager 1500 which seals the thus-formed animal chewin a package to inhibit further loss of moisture from the animal chew.

The bottom and top stamping formers 1200 and 1300 can, for example, becorresponding parts of a compression molding system of the type that iscommonly used in the plastics industry to form plastic bottle caps. In adevice of this type, billets of melt generated by the portioningmanifold 1100 are delivered to a rotating table having stations whichbear individual bottom forming plates. Filling the bottom forming platetakes place at one station, followed by compression of the billet at oneor more different stations along the rotation table. Joining of a bottomand top forming plates compresses the billet into a shape describedherein.

An embodiment of an apparatus suitable for the portioning and moldingoperations of the compression molding process illustrated in FIG. 20 isshown in FIGS. 20C and 20D. FIG. 20C is top view of the apparatus, andFIG. 20D is side view showing some aspects of it. This apparatus cantake the place of the portioning manifold 1100, the top stamping former1300, and the bottom stamping former 1200 in FIG. 20A.

In FIG. 20C, two intermeshing rotary devices are shown, each havingplates linked about the periphery of a rotating hub. The rotary deviceon the left (rotating clockwise in this view) is a portioner 1150 (akinto portioning manifold 1100 in FIG. 20A) that is adapted to work withthe rotary device on the right (rotating counter-clockwise in thisview), which is a rotary molder 1250 (combining the functionality of thebottom- and top-stamping formers 1200 and 1300 in FIG. 20A). A conveyor1290 carries formed pet chews 1 to the right, away from the rotarymolder 1250 in FIG. 20C.

In the FIG. 20C, the portioner 1150 is depicted having eight portionerplates 1170 equally spaced about the periphery of a hub 1160 thatrotates about a shaft 1180. Each portioner plate 1170 bears a void 1175(not shown in FIG. 20C) that extends completely through the portionerplate 1170, has a controlled volume (i.e., that of the desired charge tobe contained within the void 1175), and a shape that approximates theoutline of the lower molding cavities 1282 of the lower mold plates 1280of the rotary molder 1250. The portioner 1150 rotates each portionerplate 1170 past the extrudate feed line 110 to facilitate filling of theplate's void with extrudate. Filling occurs in the void of the portionerplate at the “12 o'clock” position of the portioner 1150 in FIG. 20C.The void 1175 is filled with extrudate delivered by the extrudate feedline 110, and the bolus of extrudate with which the void is filled istermed the “charge.”

After the void 1175 in the portioner plate 1170 is filled, the portionerhub 1160 rotates until the portioner plate 1170 is aligned (at the “3o'clock” position of the portioner 1150 in FIG. 20C) between upper moldplate 1270 and lower mold plate 1280 (visible in FIG. 20D) of the rotarymolder 1250. The charge is there expelled from the void into the lowerplate of the molder. Such expulsion can occur under gravity, or thecharge can be urged out of the void 1175 by a knock-out device 1195 suchas a pneumatic piston or a metal strip resiliently opposed against theupper face of the portioner plate 1170 and aligned with void 1175. Thecharge is sufficiently ductile at this point that it can be molded bythe rotary molder 1250.

Upon expulsion into the lower molding cavity 1282 of the lower moldplate 1282 (at the “9 o'clock” position of the rotary molder 1250 inFIG. 20C), the charge initially has a shape that does not completelyfill the lower molding cavity 1282, but is contained within it. Theupper mold plate 1270 does not contact the charge or the lower moldplate 1280 at this position.

Portioner 1150 is illustrated in FIGS. 20C and 20D as a rotatingdisk-shaped hub 1160 having discrete portioner plates 1170 mounted aboutits circumference. These two elements can be combined, for example inthe form of a larger disk-shaped hub 1160 which has no attachedportioner plates 1170, but which bears within the hub 1160 the voids1175 in the same relative positions about the shaft 1180 of theportioner 1150 as shown in FIGS. 20C and 20D. FIG. 20C includes a fewinformalities, in that the upper mold plates 1270 in approximately the“8 o'clock,” “9 o'clock,” and “10 o'clock” positions of the rotarymolder 1250 ought to obscure the three corresponding portioner plates1170 and all or a portion of the voids 1175 extending therethrough(since the portioner plates 1170 are interposed between the upper moldplates 1270 and the lower mold plates 1280, which are obscured by theupper mold plates in FIG. 20C). Furthermore, upper mold plates 1270should obscure portions of the conveyor 1290, but are treated astransparent for this purpose in FIG. 20C. In FIG. 20D, shafts 1264 and1180 are shown crossing multiple components (e.g., drive wheels 1162 and1262, bottom plate 1192, hub 1260, and a pair of upper and lower moldplates, even though the shaft would normally be obscured by those items(i.e., those items are treated as transparent for this purpose in FIG.20D). Similarly, the edges of hub 1260 are shown crossing several moldplates, even though those edges would normally be obscured by the plates(i.e., the plates are treated as transparent for this purpose in FIG.20D). Not shown in FIG. 20D for the purpose of illustration are hub1160, connections between mold plates and hub 1260, mold plates on the‘upper’ half of rotary molder 1250 in FIG. 20C, and mechanisms formoving, inclining, and declining mold plates.

As the lower mold plate 1280 is rotated in a horizontal plane (from the“9 o'clock” to about the “6 o'clock” position of the rotary molder 1250in FIG. 20C, the rotary molder 1250 urges the upper mold plate 1270downwardly until it contacts the lower mold plate 1280. Downward motionof upper plate 1270 is imparted by a mechanism within the hub 1260,connected by upper plate connector 1274. Prior to the upper and lowermold plates 1270 and 1280 contacting one another, the upper moldingcavity 1272 in the upper mold plate 1270 contacts the still-ductilecharge; further lowering of the upper mold plate 1270 compresses thecharge within and between the upper and lower molding cavities 1272 and1282, causing the charge to fill the cavities completely. Any excesscharge (i.e., beyond the volume defined by the closed molding cavities)can be expelled at the seam between the upper and lower mold plates 1270and 1280 and form a flash that can be removed (e.g., in tumbler 1000 inFIG. 20A). Upon contact of the upper and lower mold plates 1270 and1280, the upper and lower molding cavities 1272 and 1282 are in theirmost-closely-opposed conformation, and they are held in thisconformation momentarily as the hub 1260 of the rotary molder 1250continues to rotate. The upper and lower mold plates 1270 and 1280 canbe cooled (e.g., by a gas or liquid contacting the plates) before theplates are separated from one another. Such cooling can stiffen thenow-shaped charge and contribute to its conformational stability uponde-molding.

Beginning at about the “3 o'clock” position of the rotary molder 1250 inFIG. 20C, the upper mold plate 1270 is lifted away from the lower moldplate 1280, separating the upper and lower molding cavities 1272 and1280. The now-shaped charge can rest in or adhere to one or the other ofthe upper mold plates 1270 and 1280, and will usually rest in the lowermold plate 1280 unless it adheres to the upper mold plate 1270. Theupper mold plate 1270 appears to get smaller between the “3 o'clock” andthe “12 o'clock” position of the rotary molder 1250 in FIG. 20C becausethe distal ends of the upper and lower mold plates 1270 and 1280 arebeing inclined outwardly away from one another (i.e., they are beingopened apart outwardly and perpendicularly to the horizontal plane, likea clam shell anchored at its hinge to the hub 1260). Thisinclination/opening continues until both the upper and lower mold plates1270 and 1280 are vertical at the “12 o'clock” position in FIG. 20C. Inthis configuration, the formed charge (which is sufficiently rigid tohold its molded shape) tumbles out of the molding cavity in which it islodged onto the conveyor 1290 in the shape of a pet chew 1. In the eventthe charge adheres to the molding cavity in which it is lodged, it canbe dislodged pneumatically or mechanically, using any known device ormethod known in the molding arts.

After shaped charges are discharged from the rotary molder 1240 (at the“12 o'clock” position in FIG. 20C), the upper and lower mold plates 1270and 1280 are declined back into the horizontal position (at about the“10 o'clock” position of the rotary molder 1250 in FIG. 20C) to alignthem for having another charge deposited therebetween by the portioner1150. The upper and lower mold plates 1270 and 1280 can be cleaned orlubricated (e.g., sprayed with an edible oil) between dislodgement ofone formed charge and deposition therebetween of a fresh charge from theportioner 1150. Such cleaning and lubrication can facilitatedislodgement of formed charges and maintain cleanliness of the upper andlower molding cavities 1272 and 1282.

FIG. 20D illustrates a side view of the same apparatus shown in FIG.20C. The apparatus rests upon a floor F and is supported, for example,by several legs 1052, the precise arrangement of which is not critical.The components of the apparatus can be contained within a housing 1050.The apparatus can include a variety of supports, material inlets andoutlets, and power, heat, or coolant inlets and outlets to facilitateits operation. The housing can serve to prevent environmentalcontamination (e.g., by dust or grime) of the pet chew product and itsprecursors, can protect operators against hazards such as heat,electricity, and mechanical movement of the apparatus components. Thehousing can be openable or removable to permit access to the componentsof the apparatus and materials passing therethrough. The precisearrangement of housing, support, and access components is not critical.

In FIG. 20D, two thin, horizontally-oriented rectangles, each opposedagainst the other at one end represent an edge-on view of a pair ofrotary drive mechanisms. Portioner drive wheel 1162 drives rotation ofthe portioner 1150. Rotary molder drive wheel 1262 drives rotation ofthe rotary molder 1250. Rotations of the portioner 1150 and the rotarymolder 1250 are coordinated, so portioner plate voids 1175 are alignedwith lower molding cavities 1282 during discharge of charges from thevoids into the cavities. Such coordination facilitates proper insertionof charge into the molding cavities, complete filling of the cavitieswith charge, and minimization of wasted charge. Coordination of theportioner and rotary molder drive wheels 1162 and 1262 can be achievedby any known method such as direct perimeter-to-perimeter contact (asshown in FIG. 20D), by interlocking circumferential gears, bycoordinated drive belts, by coordinated motors, or by separate controlof each of the two wheels.

A shaft 1180 extends between the portioner drive wheel 1162 and the hub1160 to which the portioner plates 1170 are circumferentially attached.By means of this shaft 1180, torsional power applied to the portionerdrive wheel 1162 is transmitted to the hub 1160 and the portioner plates1170, resulting in their rotation. Similarly, a shaft 1264 extendsbetween the rotary molder drive wheel 1262 and the hub 1260 to whichupper mold plates 1270 and lower mold plates 1280 are attached.Torsional power applied to the rotary molder drive wheel 1262 will driverotation of the hub 1260 and the upper and lower mold plates 1270 and1280. By use of conventional mechanical components (e.g., cams,bearings, raceways, and mechanical deflectors) torsional power appliedto the shaft 1264 can also be used to drive movement of upper and lowermold plates 1270 and 1280 toward and away from one another, inclinationand declination of the upper and lower mold plates 1270 and 1280, andmechanical shaking or rattling of the plates to dislodge formed chargestherefrom.

In the portioner 1150, three plates are shown (edge-on) aligned with theextrudate feed line 110 in FIG. 20D. The top plate 1191 and the bottomplate 1192 are fixed in location relative to the extrudate feed line110. The top plate 1191 and extrudate feed line 110 are not shown inFIG. 20C. A portioner plate 1175 is shown in FIG. 20D interposed betweenthe top plate 1191 and the bottom plate 1192. That portioner plate 1170is present at the “12 o'clock” position of the portioner 1150 shown inFIG. 20C. The void 1175 in that portioner plate 1170 is aligned with theextruder feed line 110 closely opposed against the top plate 1191 andthe bottom plate 1192. The bottom plate 1192 completely obscures thevoid 1175 at its opposed face. The top plate 1191 has an orifice (notshown in the figures) extending through which extrudate can pass fromthe extrudate feed line 110 into the void 1175. The top plate 1191 alsoobscures the void 1175 as it rotates out of alignment with the orifice,thereby completely closing off the void 1175 between the top plate 1191and the bottom plate 1192, defining a fixed volume for the charge. Thatfixed volume can be selected by varying the thickness of the portionerplate 1170 (and the corresponding separation of the top and bottomplates 1191 and 1192) and the shape and dimensions of the void 1175.

As the filled portioner plate 1170 and the void 1175 carrying the chargemoves to the right in FIG. 20D (corresponding to rotation of the plate1170 to the “3 o'clock” position of the portioner 1150 in FIG. 20C), aknock-out device 1195 causes the charge to be expelled from the void1175 in the portioner plate 1170 into the lower molding cavity 1282.

In FIG. 20D, descent of the upper mold plate 1270 toward and against thelower mold plate 1280 can be seen for the mold plate pairs movingleft-to-right in the figure (i.e., the mold plates shown in the lowerhalf of FIG. 20C—the mold plates in the upper half of FIG. 20C are notshown in FIG. 20D). Also visible between the mold plates in FIG. 20D isthe charge, which does not have the shape of the upper molding cavity1272 until the upper and lower mold plates 1270 and 1280 are urgedagainst each other.

The compression molding process described herein and the apparatusillustrated in FIGS. 20C and 20D can be used to make other products inaddition to the animal chews described herein. By way of example, theycan be used in manufacture of biscuits and confections intended forhuman consumption, or for other products having a shape and compositionsuitable for compression molding.

A significant advantage of this compression molding process is that the‘twisted’ conformation of the shaft of the animal chew (see, e.g., FIG.10) can be imparted to the chew without performing a physical twistingoperation upon the chew. Instead, the ‘twisted’ conformation can be madethrough a simple molding process. In such a molding process, one lateraledge 83 of a condyle 82 of a bone-shaped chew is set substantiallydeeper into a molding plate than the opposite lateral edge 84 of thesame condyle 82. Even though the material that fills the mold is notnecessarily physically twisted, the condyle 82 nonetheless attains a‘twisted’ conformation upon molding, as can be seen from the partingline 42 (which forms at the edge at which the two molding cavities usedto form a chew, for example, the chew shown in FIG. 10, meet).

FIG. 21 illustrates a process involving simultaneous molding and cuttingof melt to form intermediate bodies which are thereafter subjected tofurther shaping prior to cooling to yield the animal chew. In thisprocess, combined melt obtained from body and filler extruders 100 and200 is fed to a coextrusion head 600 to form a continuous rope-likemelt. The melt rope is fed under pressure into matched molding cavitiesof a die roll molder 700 (side and end-on views of a nozzle used to feedthe melt rope between the rollers of the die roll molder are shown inFIGS. 21B and 21C) to yield intermediate bodies severed from the meltrope, the intermediate bodies having a shape conferred upon them by thedie roll molder 700. The intermediate bodies, which remain at asufficiently high temperature that they remain plastic, are fed into aforming system (800) which manipulates the intermediate bodies (e.g., bytwisting or bending them) to further shape them into the final desiredshape of the animal chew. Formed bodies are passed into an oven dryer900 to reduce their moisture content and thence to a tumbler 1000,cooler 1400, and packaging system 1500 as described above.

FIG. 22 illustrates a process involving formation of cuttingintermediate bodies from an extruded melt having a perimeter shape thatis approximately that of the desired perimeter shape of the final animalchew, followed by passage of the intermediate bodies through a formingsystem 500 that confers additional shape features to the intermediatebodies prior to cooling them to form the final animal chew. In thisprocess, extruded melted is delivered to a die manifold which shapes themelt into a rope-like mass having a perimeter shape that isapproximately that of the desired perimeter shape of the final animalchew. The rope-like mass is delivered to a cutter 400 that divides therope into slices cut approximately perpendicular to the long axis of therope. The slices are delivered to a forming conveyor 500 which confersshape features to the slice faces bounded by the rope perimeter. Asshown in FIGS. 22B and 22C illustrate the construction of the formingconveyor, including convex shaping members 510 (further illustrated inFIGS. 22Ci and 22Cii) and concave shaping members 520 between which theslices are compressed to confer shape thereto. The spacing between theconvex and concave shaping members 510 and 520, which are attached toseparate opposed conveyers can be adjusted to varying the imprintresolution imparted to the formed slices. After being shaped in theforming conveyor 500, the formed slices are transferred to a cooler 1400and thence to a packager 1500.

EXAMPLES

The subject matter of this disclosure is now described with reference tothe following Examples. These Examples are provided for the purpose ofillustration only, and the subject matter is not limited to theseExamples, but rather encompasses all variations which are evident as aresult of the teaching provided herein.

Example 1

Table 1 lists illustrative recipe ranges for some embodiments of theanimal chew described herein. Also listed are more specific formulas fortwo particular embodiments, designated “Harder Recipe 1” and “SofterRecipe 1” formulations. Components are listed as percentage by weight ofthe melt, prior to heating, rather than by weight percentage in thechewable matrix formed from the melt (as disclosed elsewhere in thisdisclosure). Note that the amount of water, including humectants, can besubstantially greater than the final water content of the chewablematrix of the animal chew. This difference is attributable to

TABLE 1 General Harder Softer Proportion Recipe 1 Recipe 1 ComponentsCombined to Form Melt (wt %) (wt %) (wt %) Proteins  5-20 9 11 Starches30-60 51 48 Abrasive Fibers and or Particles 3-9 7 7 Flavor and AromaEnhancers 0-6 3 2 Water (optionally including one or 24-30 25 26 morehumectants) Other ingredients (e.g., Preserva- 3-7 5 6 tives, Minerals,Vitamins, Colorants, Flavorants, Aromants, Fillers) Total 100 100

A variety of different matrix formulations were formed with varyingproportions of CRISP FILM and ELASTIGEL starches, brewer's rice, andpowdered cellulose. The effects of these proportions on setting time(results shown in FIGS. 19A and 19C), hardness (results shown in FIG.19B), and moisture retention (results shown in FIG. 19D) weredetermined.

Example 2

Another exemplary formula for the components that are combined to form amelt as described herein is shown in Table 2. As in Example 1,proportions shown are weight of each ingredient as a percentage of theweight of the combination. The water content of this combination isgreater than the final water content of animal chews formed from themelt prepared from the combination, owing to water loss from thecomposition during melt formation and subsequent controlled drying ofthe formed animal chew.

In each of Table 2A, 2B, and 2C, STTP is sodium tripolyphosphate. Eachof CRISPFILM and ELASTIGEL is a trademark of Corn Products DevelopmentInc.

TABLE 2A Melt Ingredients. Proportion of Ingredient(s), wt % of totalformula Formula Name Ingredient(s) A B C D E F Ground Brewers Rice 38.745.5 40.6 49.6 36.3 47.1 Water 23.1 23.1 23.1 23.1 23.1 23.1 Chickenby-product meal 8.39 8.39 8.39 8.39 8.39 8.39 CRISPFILM Brand 7.51 0.008.00 0.80 2.85 0.00 Modified Food Starch ELASTIGEL Brand 1.88 4.80 3.363.97 8.00 8.00 Modified Food Starch Cellulose Powder 7.04 4.80 3.20 0.808.00 0.00 Propylene Glycol 5.02 5.02 5.02 5.02 5.02 5.02 Powdered Gypsum2.11 2.11 2.11 2.11 2.11 2.11 Bone Phosphate 2.11 2.11 2.11 2.11 2.112.11 Flavorants, Aromants, 2.16 2.16 2.16 2.16 2.16 2.16 and ColorantsSTPP 1.00 1.00 1.00 1.00 1.00 1.00 Vitamins and Minerals 0.106 0.1060.106 0.106 0.106 0.106 Preservative(s) 0.906 0.906 0.906 0.906 0.9060.906 Approximate Starch 38.7 39.8 41.8 43.0 37.9 43.8 Content, wt %

TABLE 2B Melt Ingredients. Proportion of Ingredient(s), wt % of totalformula Formula Name Ingredient(s) G H I J K L Ground Brewers Rice 47.136.3 36.3 45.6 47.1 40.6 Water 23.1 23.1 23.1 23.1 23.1 23.1 Chickenby-product meal 8.39 8.39 8.39 8.39 8.39 8.39 CRISPFILM Brand 0.00 8.008.00 4.76 8.00 4.32 Modified Food Starch ELASTIGEL Brand 0.00 8.00 2.840.00 0.00 4.32 Modified Food Starch Cellulose Powder 8.00 2.80 8.00 4.760.00 5.88 Propylene Glycol 5.02 5.02 5.02 5.02 5.02 5.02 Powdered Gypsum2.11 2.11 2.11 2.11 2.11 2.11 Bone Phosphate 2.11 2.11 2.11 2.11 2.112.11 Flavorants, Aromants, 2.16 2.16 2.16 2.16 2.16 2.16 and ColorantsSTPP 1.00 1.00 1.000 1.000 1.000 1.000 Vitamins and Minerals 0.106 0.1060.106 0.106 0.106 0.106 Preservative(s) 0.906 0.906 0.906 0.906 0.9060.906 Approximate Starch 37.0 42.5 38.0 40.0 44.1 39.4 Content, wt %

TABLE 2C Melt Ingredients. Proportion of Ingredient(s), wt % of totalformula Formula Name Ingredient(s) M N O P Q R S Ground Brewers Rice45.6 40.6 55.1 31.1 33.7 37.1 37 Water 23.1 23.1 23.1 23.1 23.1 16.9 14Chicken by-product meal 8.39 8.39 8.39 8.39 8.39 8.55 15 CRISPFILM Brand4.76 3.32 0.00 8.00 7.51 8.00 — Modified Food Starch ELASTIGEL Brand4.80 8.00 0.00 8.00 1.88 1.91 — Modified Food Starch Waxy Corn Starch —— — — — — 5 Cellulose Powder 0.00 3.24 0.00 8.00 7.04 7.50 10 PropyleneGlycol 5.02 5.02 5.02 5.02 5.02 5.00 5 Supplement (see notes) — — — —5.00 5.00 5 Powdered Gypsum 2.11 2.11 2.11 2.11 2.11 2.15 2 BonePhosphate 2.11 2.11 2.11 2.11 2.11 2.15 2 Flavorants, Aromants, 2.162.16 2.16 2.16 2.16 2.15 2 and Colorants STPP 1.000 1.000 1.000 1.0001.00 2.20 1 Vitamins and Minerals 0.106 0.106 0.106 0.106 0.106 0.1090.1 Preservative(s) 0.906 0.906 0.906 0.906 0.906 1.27 1 ApproximateStarch 441 41.7 43.2 38.4 38.7-43.7 42.3 44.0 Content, wt %

Note: In Table 2C, the ingredient identified as “Supplement” can be anyone or more of a gelatin, a gluten (e.g., wheat or gluten), acarrageenan, a casein (e.g., sodium or calcium caseinate), dextrose, adextrin, protein isolates (e.g., wheat protein isolate), andprotein-containing vegetable extracts (e.g., soy concentrates). FormulaS is a variant of formula G in which the supplement is a dextrin,illustrating that dextrin can contribute both to the starch content ofthe formula as well as conferring favorable processing characteristicsto it (e.g., reducing the amount of water necessary to render the matrixprocessable and chewable).

TABLE 3 List of Part Numbers and Abbreviations in Figures.   1 Pet Chew 10 Body  12 Nub  14 Ridge  16 Bulge  17 Topographical Characters  18Visible inclusions  20 First Surface  22 First Portion of Body  30Second Surface  32 Second Portion of Body  40 Transitional Surface  42Parting Line  44 Chamfer  50 Cavity (within or through Body)  52Intermediate Portion  55 Filling (within Cavity)  60 Interior of Body 70 Shaft  80 End (of Pet Chew)  82 Condyle  83 One Lateral Edge  84Other Lateral Edge  90 Sheath  100 Body Extruder  110 Extrudate FeedLine  200 Filling Extruder  300 Die Manifold  400 Cutter  500 FormingConveyor  510 convex shaping member  520 concave shaping member  600Coextrusion Head  700 Die Roll Molder  800 Forming System  900 OvenDryer 1000 Tumbler 1050 Housing 1052 Legs 1100 Portioning Manifold 1150Portioner 1160 Hub 1162 Drive Wheel 1170 Portioner Plate 1175 Void 1180Shaft 1191 Top Plate 1192 Bottom Plate 1195 Knock-Out Device 1200 BottomStamping Former 1250 Rotary Molder 1260 Hub 1262 Drive Wheel 1264 Shaft1270 Upper Mold Plate 1272 Upper Molding Cavity 1274 Upper PlateConnector 1280 Lower Mold Plate 1282 Lower Molding Cavity 1290 Conveyor1300 Top Stamping Former 1400 Cooler 1500 Packager R Radius of Shaftcurvature F Floor

The disclosure of every patent, patent application, and publicationcited herein is hereby incorporated herein by reference in its entirety.

While this subject matter has been disclosed with reference to specificembodiments, it is apparent that other embodiments and variations can bedevised by others skilled in the art without departing from the truespirit and scope of the subject matter described herein. The appendedclaims include all such embodiments and equivalent variations.

What is claimed is:
 1. An animal chew having a consumable portion, theconsumable portion comprising a chewable matrix and having dimensionsselected to fit within an oral cavity of an animal, wherein the chewablematrix comprises: i) about 9-17 wt % protein, ii) about 30-40 wt %starch, the starch providing from about 10% to about 20% amylose byweight of the chewable matrix, iii) water and, optionally, a humectant,in amounts sufficient to confer chewable plasticity to the chewablematrix, iv) a temporally efficacious amount of an orally activeingredient, and v) at least 0.5 wt % of an edible saccharidic processingaid.
 2. The chew of claim 1, wherein the processing aid isnon-cariogenic.
 3. The chew of claim 1, wherein the processing aid isone or more of a monosaccharide, a disaccharide, or a mixture ofsaccharides.
 4. The chew of claim 1, wherein the processing aid is aselected from the group consisting of dextrose, fructose, sucrose,mannitol, sorbitol, xylitol, and mixtures of these.
 5. The chew of claim1, wherein the processing aid is an oligosaccharide consisting of from 3to 9 saccharide units.
 6. The chew of claim 5, wherein the processingaid is a dextrin or a maltodextrin.
 7. The chew of claim 1, wherein thechewable matrix comprises at least 1 wt % of the processing aid.
 8. Thechew of claim 1, wherein the chewable matrix comprises at least 0.5-1 wt% of one or more of the processing aids.
 9. A method of forming achewable matrix for an animal chew, the method comprising combining andthoroughly mixing to form a mixture: i) about 5-20 wt % protein, ii) atleast about 30-40 wt % starch, iii) water and, optionally, a humectant,iv) an orally active ingredient, and v) an edible saccharidic processingaid; heating the mixture to a processing temperature above agelatinization temperature of the starch to form a melt; shaping aportion of the melt into a matrix having dimensions selected to fitwithin an oral cavity of an animal; and cooling the matrix below thegelatinization temperature to yield the chewable matrix comprising 30-40wt % starch, wherein the starch provides from about 10 wt % to about 20wt % amylose by weight of the chewable matrix, wherein proportions ofwater and humectant are selected in amounts sufficient to conferchewable plasticity to the cooled chewable matrix and wherein an amountof the orally active ingredient is selected such that the chewablematrix comprises a temporally efficacious amount of the ingredient, andwherein the processing aid is included in the mixture in an amountsufficient to reduce viscosity of the mixture at the processingtemperature, relative to the same mixture lacking the processing aid.10. The method of claim 9, wherein the mixture includes at least 0.5 wt%, or optionally 0.5-1 wt %, of the processing aid.
 11. The method ofclaim 9, wherein the processing aid is selected from the groupconsisting of monosaccharides, disaccharides, oligosaccharidesconsisting of from 3 to 9saccharide units, and mixtures of these. 12.The method of claim 9, wherein the portion is shaped by a process whichincludes compression molding.
 13. The method of claim 12, wherein theshaped portion of the matrix has a surface conformation that includesnumerous nubs, ridges, or both.
 14. The method of claim 9, wherein theorally active ingredient is a dental prophylactic ingredient.
 15. In ananimal chew having a body with an outer surface and being intended forconsumption by an animal, the improvement comprising invaginating theouter surface of the body to increase the surface-to-volume ratio of thechew to an extent that any portion of the chew that is swallowed by theanimal will normally be digested within about four hours afterswallowing.
 16. In an animal chew having a body with an outer surfaceand being intended for consumption by an animal, the improvementcomprising invaginating the outer surface of the body to increase thesurface-to-volume ratio of the chew to a value in excess of
 8. 17. Theimprovement of claim 16, wherein the surface-to-volume ratio of the chewis increased to a value in excess of
 12. 18. In an animal chew having abody with an outer surface and being intended for consumption by ananimal, the improvement comprising altering the shape of the body toinclude break points configured to yield fragments of a predictable sizeupon fracture of the chew at the break points, whereby no fragment has asurface-to-volume ratio less than
 10. 19. An animal chew having aconsumable portion, the consumable portion comprising a chewable matrixand having dimensions selected to fit within an oral cavity of ananimal, wherein the chewable matrix comprises: i) about 9-17 wt %protein, ii) about 30-40 wt % starch, the starch providing from about10% to about 20% amylose by weight of the chewable matrix, iii) waterand, optionally, a humectant, in amounts sufficient to confer chewableplasticity to the chewable matrix, iv) a temporally efficacious amountof an orally active ingredient, and v) at least 0.5-1 wt % of an ediblesaccharidic processing aid, and wherein the surface-to-volume ratio ofthe chew is at least
 8. 20. The chew of claim 19, wherein thesurface-to-volume ratio of the chew is at least
 10. 21. The chew ofclaim 19, wherein the surface-to-volume ratio of the chew is at least12.
 22. The chew of claim 1, wherein the chew has a chew time of 1-30minutes or of 2-5 minutes.
 23. The chew of claim 19, wherein the chewhas a chew time of 1-30 minutes or of 2-5 minutes.
 24. The chew of claim19, wherein the shape of the chew includes break points wherein breakingthe chew at the break points yields no fragment having asurface-to-volume ratio less than
 10. 25. The chew of claim 1, whereinthe chewable matrix exhibits friability so that all of the consumableportion of the chew can be consumed by the animal in not more than fourhours, and optionally not more than two hours, one hour, or 30, 20, 10,5, 4, 3 or 2 minutes, or 1 minute, of composite chewing time.
 26. Thechew of claim 1, wherein the consumable portion of the chew can beconsumed by the animal from about 30 seconds to no more than 2, 5, 10,20, 30, 60, 90, 120 or 240 minutes of composite chewing time.
 27. Thechew of claim 1, wherein the consumable portion of the chew can beconsumed by the animal from about 60 seconds to no more than 2, 5, 10,20, 30, 60, 90 or 120 minutes of composite chewing time.
 28. The chew ofclaim 1, wherein the consumable portion of the chew can be consumed bythe animal from about 2 minutes to no more than 6 minutes, or no morethan 60 minutes, of composite chewing time.
 29. The chew of claim 1,wherein the consumable portion of the chew can be consumed by the animalfrom about 10 minutes to no more than 30 minutes of composite chewingtime.
 30. The chew of claim 1, wherein the consumable portion of thechew can be consumed by the animal from about 1 minute to no more than 2minutes, or no more than 30 minutes, of composite chewing time.
 31. Thechew of claim 1, wherein the chewable matrix exhibits integrity so thatthe consumable portion of the chew will remain non-consumed by theanimal after at least 30 seconds, and optionally at least one minute, ofcomposite chewing time.
 32. The chew of claim 1, wherein the chewablematrix exhibits integrity so that the consumable portion of the chewwill remain non-consumed by the animal after at least 2 minutes, andoptionally after at least 5, 10, 20, 30, 60, 90 or 120 minutes, ofcomposite chewing time.
 33. The chew of claim 1, wherein the chewablematrix exhibits rigidity so that the chewable matrix does not fractureuntil it has been chewed at least about 10 times, and optionally atleast about 25, 100, 500, or 2000 times, by the animal.
 34. The chew ofclaim 1, wherein the chewable matrix exhibits ductility so that theanimal is able to leave a visible indentation in the surface of thechewable matrix upon biting the chew one time.